Information configuration method, data receiving method, and device

ABSTRACT

An information configuration method, a data receiving method, and a device are provided. A first network device configures a first resource set group of a physical downlink control channel set for user equipment, and configures for the user equipment, a second resource set group of a physical downlink control channel for retransmission, where the physical downlink control channel for retransmission is a physical downlink control channel for retransmission corresponding to downlink data indicated by a physical downlink control channel in at least one subset of the physical downlink control channel set. The first network device sends information about the first resource set group and information about the second resource set group to the user equipment.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 16/119,372, filed on Aug. 31, 2018, which is acontinuation application of U.S. patent application Ser. No. 15/010,607,filed on Jan. 29, 2016, now U.S. Pat. No. 10,104,648, which is acontinuation of International Application No. PCT/CN2013/080643, filedon Aug. 1, 2013. All of the afore-mentioned patent applications arehereby incorporated by reference in their entireties.

TECHNICAL FIELD

The present invention relates to communications technologies, and inparticular, to an information configuration method, a data receivingmethod, and a device.

BACKGROUND

By using a coordinated multipoint transmission/reception (CoMP forshort) technology, multiple network devices can share channel stateinformation and user data information, to perform joint multipointtransmission or reception, so as to implement effective utilization ofnetwork resources. However, all existing CoMP technologies are based onan ideal backhaul, and the ideal backhaul means that information may beexchanged between different network devices at a low delay and at a highthroughput rate. The network device herein may be a base station, aremote radio head, or the like.

In an actual scenario, because of a factor such as an environment ordifferent manufacturers, it is quite difficult to implement an idealbackhaul. For example, for multiple network devices, there may be anideal backhaul between some network devices, for example, an idealbackhaul between multiple RRHs controlled by one base station; however,there may also be a non-ideal backhaul between some other networkdevices.

In an ideal backhaul case, a dynamic point selection technology or adynamic point blanking technology (dynamic point selection or dynamicpoint blanking) may be used, so that some network devices may beselected to transmit data to user equipment on some time-frequencyresources in a subframe, and other network devices may not transmit dataon these time-frequency resources.

In a communications system, a hybrid automatic repeat request (HARQ)technology may be used. In the HARQ technology, a network devicetransmits data in one data block to user equipment, and if the userequipment correctly receives the data, the user equipment feeds back apositive acknowledgement (ACK for short), or if the user equipment doesnot correctly receive the data, the user equipment feeds back a negativeacknowledgement (NACK for short). If the network device receives theNACK, the network device performs retransmission of the data block, orif the network device receives the ACK, the network device transmits anew data block.

Regardless of initial transmission or retransmission of a data block, inan ideal backhaul case, network devices may quickly share informationsuch as a channel state, or transmitted or received data; therefore, ina case in which data sent by a network device is not correctly receivedby UE, the network device may dynamically select another network devicefor data retransmission. Therefore, switching between multiple networkdevices may be dynamically performed for initial transmission andretransmission in an HARQ process, so as to obtain a multipointcoordination gain.

In a non-ideal backhaul scenario, there is a relatively large delay forinformation exchange between multiple network devices; therefore, anetwork device is likely fail to learn a data sending status of anothernetwork device in a timely manner, for example, fails to learn whetherdata sent by another network device is correctly received by UE.Therefore, a dynamic retransmission solution in an ideal backhaulscenario cannot be used, and in the non-ideal backhaul scenario, acoordination gain cannot be obtained by means of coordination betweenmultiple network devices in an aspect of data transmission.

For a same network device, the network device may perform coordinationin an aspect of data transmission by means of quick information exchangebetween multiple modules in the network device, so that a coordinationgain is obtained. However, the solution to implementing quickinformation exchange between multiple modules is relatively complex.

SUMMARY

Embodiments of the present invention provide an informationconfiguration method, a data receiving method, and a device, so that acoordination gain can still be obtained without quick informationexchange.

According to a first aspect, an information configuration method isprovided, including:

-   -   configuring, by a first network device, a first resource set        group of a physical downlink control channel set for user        equipment, and configuring, for the user equipment, a second        resource set group of a physical downlink control channel for        retransmission, where the physical downlink control channel for        retransmission is a physical downlink control channel for        retransmission corresponding to downlink data indicated by a        physical downlink control channel in at least one subset of the        physical downlink control channel set; and    -   sending, by the first network device, information about the        first resource set group and information about the second        resource set group to the user equipment.

With reference to the first aspect, in a first possible implementationmanner, after the sending information about the second resource setgroup to the user equipment, the method further includes: sending, bythe first network device, at least one physical downlink control channelof the physical downlink control channel in the at least one subset tothe user equipment, where the at least one physical downlink controlchannel carries first control information, and the first controlinformation includes scheduling information of the downlink data; and/orsending, by a second network device, at least one physical downlinkcontrol channel of the physical downlink control channel in the at leastone subset to the user equipment, where the at least one physicaldownlink control channel carries first control information, the firstcontrol information includes scheduling information of the downlinkdata, and the second network device is controlled by the first networkdevice.

With reference to the first aspect or the first possible implementationmanner of the first aspect, in a second possible implementation manner,the information about the second resource set group includes acorrespondence, and the correspondence is a correspondence between thephysical downlink control channel in the at least one subset and thesecond resource set group or a correspondence between the at least onesubset and the second resource set group.

With reference to the first aspect or the first possible implementationmanner of the first aspect, in a third possible implementation manner,the physical downlink control channel in the at least one subset furtherindicates the second resource set group.

With reference to the first aspect or any one of the possibleimplementation manners of the first aspect, in a fourth possibleimplementation manner, the method further includes: for the physicaldownlink control channel in the at least one subset, notifying, by thefirst network device, the user equipment of configuration information ofa physical uplink control channel and/or transmit power configurationinformation of the physical uplink control channel, where the physicaluplink control channel is used to carry acknowledgement information ofthe downlink data indicated by the physical downlink control channel.

With reference to any one of the first possible implementation manner tothe fourth possible implementation manner of the first aspect, in afifth possible implementation manner, after the sending, by the firstnetwork device, at least one physical downlink control channel of thephysical downlink control channel in the at least one subset to the userequipment, the method further includes: if the second network devicereceives negative acknowledgement information sent by the userequipment, sending, by the second network device to the user equipment,at least one of the physical downlink control channel that is forretransmission and in the second resource set group, where the at leastone of the physical downlink control channel for retransmission carriessecond control information, and the second control information includesscheduling information of downlink data corresponding to the at leastone of the physical downlink control channel for retransmission; or

-   -   after the sending, by a second network device, at least one        physical downlink control channel of the physical downlink        control channel in the at least one subset to the user        equipment, the method further includes: if the first network        device receives negative acknowledgement information sent by the        user equipment, sending, by the first network device to the user        equipment, the at least one of the physical downlink control        channel that is for retransmission and in the second resource        set group, where the at least one of the physical downlink        control channel for retransmission carries second control        information, and the second control information includes        scheduling information of downlink data corresponding to the at        least one of the physical downlink control channel for        retransmission.

With reference to the first aspect or any one of the possibleimplementation manners of the first aspect, in a sixth possibleimplementation manner, the method further includes: for the physicaldownlink control channel in the at least one subset, notifying, by thefirst network device, the user equipment of one group of commonreference signal CRS rate matching information, where at least one pieceof CRS rate matching information in the group of CRS rate matchinginformation includes at least two pieces of CRS pattern information, andthe at least one piece of CRS rate matching information in the group ofCRS rate matching information is used for rate matching for the downlinkdata indicated by the physical downlink control channel in the at leastone subset.

With reference to the first aspect or any one of the possibleimplementation manners of the first aspect, in a seventh possibleimplementation manner, the information about the first resource setgroup includes time-frequency resource configuration information of thephysical downlink control channel set; and/or the information about thesecond resource set group includes time-frequency resource configurationinformation of the physical downlink control channel for retransmission.

According to a second aspect, a data receiving method is provided,including:

-   -   receiving, by user equipment, at least one physical downlink        control channel according to information about a first resource        set group sent by a first network device, acquiring first        control information carried on the at least one physical        downlink control channel, and receiving downlink data according        to scheduling information that is of the downlink data and        included in the first control information, where the first        resource set group is a resource set that is of a physical        downlink control channel set and preconfigured by the first        network device for the user equipment, and the at least one        physical downlink control channel is a physical downlink control        channel in at least one subset of the physical downlink control        channel set; and    -   detecting, by the user equipment in a second resource set group        corresponding to information about the second resource set group        sent by the first network device, a physical downlink control        channel for retransmission corresponding to the downlink data,        where the second resource set group is a resource set that is of        the physical downlink control channel for retransmission and        preconfigured by the first network device for the user        equipment.

With reference to the second aspect, in a first possible implementationmanner, before the detecting, by the user equipment in a second resourceset group, a physical downlink control channel for retransmissioncorresponding to the downlink data, the method further includes:

-   -   determining, by the user equipment according to the at least one        received physical downlink control channel and a correspondence        included in the information about the second resource set group,        the second resource set group corresponding to retransmission of        the downlink data, where the correspondence is a correspondence        between the physical downlink control channel in the at least        one subset and the second resource set group, or the        correspondence is a correspondence between the subset of the        physical downlink control channel set and the second resource        set group, and the correspondence is sent by the first network        device.

With reference to the second aspect, in a second possible implementationmanner, before the detecting, by the user equipment in a second resourceset group corresponding to information about the second resource setgroup sent by the first network device, a physical downlink controlchannel for retransmission corresponding to the downlink data, themethod further includes:

-   -   determining, by the user equipment according to an indication in        the at least one received physical downlink control channel, the        second resource set group corresponding to retransmission of the        downlink data.

With reference to the second aspect or any one of the possibleimplementation manner of the second aspect, in a third possibleimplementation manner, the method further includes: the method furtherincludes: for the physical downlink control channel in the at least onesubset, receiving, by the user equipment, configuration information thatis of a physical uplink control channel and notified by the firstnetwork device; and

-   -   after the receiving downlink data according to scheduling        information that is of the downlink data and included in the        first control information, the method further includes:        determining, by the user equipment according to the        configuration information of the physical uplink control        channel, resource information of the physical uplink control        channel corresponding to the downlink data, and sending        acknowledgement information of the downlink data according to        the resource information of the physical uplink control channel.

With reference to the third possible implementation manner of the secondaspect, in a fourth possible implementation manner, after the receivingdownlink data according to scheduling information that is of thedownlink data and included in the first control information, the methodfurther includes:

-   -   if the acknowledgement information is negative acknowledgement        information, receiving, by the user equipment according to the        information about the second resource set group, at least one of        the physical downlink control channel that is for retransmission        and in the second resource set group, where the physical        downlink control channel for retransmission carries second        control information; and    -   receiving, by the user equipment, retransmitted downlink data        according to scheduling information included in the second        control information, where the scheduling information is        scheduling information of the downlink data corresponding to the        physical downlink control channel for retransmission.

With reference to the third possible implementation manner or the fourthpossible implementation manner of the second aspect, in a fifth possibleimplementation manner, before the sending acknowledgement information ofthe downlink data according to the resource information of the physicaluplink control channel, the method further includes: for the physicaldownlink control channel in the at least one subset, receiving, by theuser equipment, transmit power configuration information that is of thephysical uplink control channel and notified by the first networkdevice; and

-   -   the sending acknowledgement information of the downlink data        according to the resource information of the physical uplink        control channel includes: determining, by the user equipment,        transmit power information of the physical uplink control        channel according to the transmit power configuration        information, and sending the acknowledgement information of the        downlink data according to the resource information and the        transmit power information of the physical uplink control        channel.

With reference to the fifth possible implementation manner of the secondaspect, in a sixth possible implementation manner, the transmit powerconfiguration information includes reference signal power; and

-   -   the determining, by the user equipment, transmit power        information of the physical uplink control channel according to        the transmit power configuration information, and sending the        acknowledgement information of the downlink data according to        the resource information and the transmit power information of        the physical uplink control channel includes:    -   determining, by the user equipment, a downlink path loss        estimate according to the reference signal power, determining        transmit power of the physical uplink control channel according        to the downlink path loss estimate, and sending the        acknowledgement information of the downlink data according to        the resource information and the transmit power of the physical        uplink control channel.

With reference to the second aspect or any one of the possibleimplementation manners of the second aspect, in a seventh possibleimplementation manner, before the receiving downlink data according toscheduling information that is of the downlink data and included in thefirst control information, the method further includes:

-   -   for the physical downlink control channel in the at least one        subset, receiving, by the user equipment, one group of common        reference signal CRS rate matching information notified by the        first network device, where at least one piece of CRS rate        matching information in the group of CRS rate matching        information includes at least two pieces of CRS pattern        information; and    -   before the receiving downlink data according to scheduling        information that is of the downlink data and included in the        first control information, including: performing, by the user        equipment by using the at least one piece of CRS rate matching        information in the group of CRS rate matching information, rate        matching on the downlink data indicated by the physical downlink        control channel in the at least one subset.

According to a third aspect, a network device is provided, including:

-   -   a configuring unit, configured to: configure a first resource        set group of a physical downlink control channel set for user        equipment, and configure, for the user equipment, a second        resource set group of a physical downlink control channel for        retransmission, where the physical downlink control channel for        retransmission is a physical downlink control channel for        retransmission corresponding to downlink data indicated by a        physical downlink control channel in at least one subset of the        physical downlink control channel set; and    -   a sending unit, configured to send information about the first        resource set group and information about the second resource set        group to the user equipment.

With reference to the third aspect, in a first possible implementationmanner, the sending unit is further configured to: after sending theinformation about the second resource set group to the user equipment,send at least one physical downlink control channel of the physicaldownlink control channel in the at least one subset to the userequipment, where the at least one physical downlink control channelcarries first control information, and the first control informationincludes scheduling information of the downlink data.

With reference to the third aspect or the first possible implementationmanner of the third aspect, in a second possible implementation manner,the information about the second resource set group sent by the sendingunit to the user equipment includes a correspondence, and thecorrespondence is a correspondence between the physical downlink controlchannel in the at least one subset and the second resource set group ora correspondence between the at least one subset and the second resourceset group.

With reference to the third aspect or the first possible implementationmanner of the third aspect, in a third possible implementation manner,the physical downlink control channel that is in the at least one subsetand sent by the sending unit to the user equipment further indicates thesecond resource set group.

With reference to the third aspect or any one of the possibleimplementation manners of the third aspect, in a fourth possibleimplementation manner, the sending unit is further configured to: forthe physical downlink control channel in the at least one subset, notifythe user equipment of configuration information of a physical uplinkcontrol channel and/or transmit power configuration information of thephysical uplink control channel, where the physical uplink controlchannel is used to carry acknowledgement information of the downlinkdata indicated by the physical downlink control channel.

With reference to any one of the first possible implementation manner tothe fourth possible implementation manner of the third aspect, in afifth possible implementation manner, the network device is a firstnetwork device;

-   -   the network device further includes a receiving unit, configured        to receive negative acknowledgement information sent by the user        equipment; and    -   the sending unit is further configured to: after the receiving        unit receives the negative acknowledgement information, send, to        the user equipment, at least one of the physical downlink        control channel that is for retransmission and in the second        resource set group, where the at least one of the physical        downlink control channel for retransmission carries second        control information, the second control information includes        scheduling information of downlink data corresponding to the at        least one of the physical downlink control channel for        retransmission, the downlink data corresponding to the at least        one of the physical downlink control channel for retransmission        is sent by a second network device to the user equipment, and        the second network device is controlled by the first network        device.

With reference to the third aspect or any one of the possibleimplementation manners of the third aspect, in a sixth possibleimplementation manner, the sending unit is further configured to: forthe physical downlink control channel in the at least one subset, notifythe user equipment of one group of common reference signal CRS ratematching information, where at least one piece of CRS rate matchinginformation in the group of CRS rate matching information includes atleast two pieces of CRS pattern information, and the at least one pieceof CRS rate matching information in the group of CRS rate matchinginformation is used for rate matching for the downlink data indicated bythe physical downlink control channel in the at least one subset.

With reference to the third aspect or any one of the possibleimplementation manners of the third aspect, in a seventh possibleimplementation manner, the information about the first resource setgroup sent by the sending unit includes time-frequency resourceconfiguration information of the physical downlink control channel set,and/or the information about the second resource set group sent by thesending module includes time-frequency resource configurationinformation of the physical downlink control channel for retransmission.

According to a fourth aspect, user equipment is provided, including:

-   -   a storage unit, configured to: store information that is about a        first resource set group of a physical downlink control channel        set and sent by a first network device to the user equipment in        advance, and store information that is about a second resource        set group of a physical downlink control channel for        retransmission and sent by the first network device to the user        equipment in advance;    -   an acquiring unit, configured to: receive at least one physical        downlink control channel according to the information that is        about the first resource set group and stored by the storage        unit, acquire first control information carried on the at least        one physical downlink control channel, and receive downlink data        according to scheduling information that is of the downlink data        and included in the first control information, where the at        least one physical downlink control channel is a physical        downlink control channel in at least one subset of the physical        downlink control channel set; and    -   a processing unit, configured to detect, in the second resource        set group corresponding to the information that is about the        second resource set group and stored by the storage unit, the        physical downlink control channel for retransmission        corresponding to the downlink data.

With reference to the fourth aspect, in a first possible implementationmanner, the information that is about the second resource set group andstored by the storage unit includes a correspondence, and thecorrespondence is a correspondence between the physical downlink controlchannel in the at least one subset and the second resource set group, orthe correspondence is a correspondence between the subset of thephysical downlink control channel set and the second resource set group;and

-   -   the processing unit is further configured to: before detecting,        in the second resource set group, the physical downlink control        channel for retransmission corresponding to the downlink data,        determine, according to the correspondence stored by the storage        unit and the at least one physical downlink control channel        received by the acquiring unit, the second resource set group        corresponding to retransmission of the downlink data.

With reference to the fourth aspect, in a second possible implementationmanner, the processing unit is further configured to determine,according to an indication in the at least one physical downlink controlchannel received by the acquiring module, the second resource set groupcorresponding to retransmission of the downlink data.

With reference to the fourth aspect or either of the possibleimplementation manners of the fourth aspect, in a third possibleimplementation manner, the acquiring unit is further configured to: forthe physical downlink control channel in the at least one subset,receive configuration information that is of a physical uplink controlchannel and notified by the first network device;

-   -   the processing unit is further configured to: after the        acquiring unit receives the downlink data according to the        scheduling information that is of the downlink data and included        in the first control information, determine, according to the        configuration information that is of the physical uplink control        channel and acquired by the acquiring unit, resource information        of the physical uplink control channel corresponding to the        downlink data; and    -   the user equipment further includes a sending unit, configured        to send acknowledgement information of the downlink data        according to the resource information that is of the physical        uplink control channel and determined by the processing unit.

With reference to the third possible implementation manner of the fourthaspect, in a fourth possible implementation manner, the acquiring unitis further configured to: if the acknowledgement information sent by thesending unit is negative acknowledgement information, receive, accordingto the information about the second resource set group, at least one ofthe physical downlink control channel that is for retransmission and inthe second resource set group, where the physical downlink controlchannel for retransmission carries second control information; andreceive retransmitted downlink data according to scheduling informationincluded in the second control information, where the schedulinginformation is scheduling information of the downlink data correspondingto the physical downlink control channel for retransmission.

With reference to the third possible implementation manner or the fourthpossible implementation manner of the fourth aspect, in a fifth possibleimplementation manner, the acquiring unit is further configured to: forthe physical downlink control channel in the at least one subset,receive transmit power configuration information that is of the physicaluplink control channel and notified by the first network device; and

-   -   the sending unit is specifically configured to send, in the        following manner, the acknowledgement information of the        downlink data according to the resource information that is of        the physical uplink control channel and determined by the        processing unit: determining transmit power information of the        physical uplink control channel according to the transmit power        configuration information acquired by the acquiring unit, and        sending the acknowledgement information of the downlink data        according to the resource information and the transmit power        information of the physical uplink control channel.

With reference to the fifth possible implementation manner of the fourthaspect, in a sixth possible implementation manner, the transmit powerconfiguration information received by the acquiring unit includesreference signal power; and

-   -   the sending unit is specifically configured to: in the following        manner, determine the transmit power information of the physical        uplink control channel according to the transmit power        configuration information acquired by the acquiring unit, and        send the acknowledgement information of the downlink data        according to the resource information and the transmit power        information of the physical uplink control channel: determining        a downlink path loss estimate according to the reference signal        power, determining transmit power of the physical uplink control        channel according to the downlink path loss estimate, and        sending the acknowledgement information of the downlink data        according to the resource information and the transmit power of        the physical uplink control channel.

With reference to the fourth aspect or any one of the possibleimplementation manners of the fourth aspect, in a seventh possibleimplementation manner, the acquiring unit is further configured to: forthe physical downlink control channel in the at least one subset,receive one group of common reference signal CRS rate matchinginformation notified by the first network device, where at least onepiece of CRS rate matching information in the group of CRS rate matchinginformation includes at least two pieces of CRS pattern information; and

-   -   the acquiring module is further configured to: before receiving        the downlink data, perform, by using the at least one piece of        CRS rate matching information in the group of CRS rate matching        information, rate matching on the downlink data indicated by the        physical downlink control channel in the at least one subset.

According to a fifth aspect, a network device is provided, including:

-   -   a processor, configured to: configure a first resource set group        of a physical downlink control channel set for user equipment,        and configure, for the user equipment, a second resource set        group of a physical downlink control channel for retransmission,        where the physical downlink control channel for retransmission        is a physical downlink control channel for retransmission        corresponding to downlink data indicated by a physical downlink        control channel in at least one subset of the physical downlink        control channel set; and    -   a transmitter, configured to send, to the user equipment,        information about the first resource set group and information        about the second resource set group that are configured by the        processor.

With reference to the fifth aspect, in a first possible implementationmanner, the transmitter is further configured to: after sending theinformation about the second resource set group to the user equipment,send at least one physical downlink control channel of the physicaldownlink control channel in the at least one subset to the userequipment, where the at least one physical downlink control channelcarries first control information, and the first control informationincludes scheduling information of the downlink data.

With reference to the fifth aspect or the first possible implementationmanner of the fifth aspect, in a second possible implementation manner,the information about the second resource set group sent by thetransmitter includes a correspondence, and the correspondence is acorrespondence between the physical downlink control channel in the atleast one subset and the second resource set group or a correspondencebetween the at least one subset and the second resource set group.

With reference to the first possible implementation manner of the fifthaspect, in a third possible implementation manner, the physical downlinkcontrol channel that is in the at least one subset and sent by thetransmitter to the user equipment further indicates the second resourceset group.

With reference to the fifth aspect or any one of the possibleimplementation manners of the fifth aspect, in a fourth possibleimplementation manner, the transmitter is further configured to: for thephysical downlink control channel in the at least one subset, notify theuser equipment of configuration information of a physical uplink controlchannel and/or transmit power configuration information of the physicaluplink control channel, where the physical uplink control channel isused to carry acknowledgement information.

With reference to the fifth aspect or any one of the possibleimplementation manners of the fifth aspect, in a fifth possibleimplementation manner, the network device is a first network device, thenetwork device further includes a receiver, configured to receivenegative acknowledgement information sent by the user equipment, and thetransmitter is further configured to: after the receiver receives thenegative acknowledgement information, send, to the user equipment, atleast one of the physical downlink control channel that is forretransmission and in the second resource set group, where the at leastone of the physical downlink control channel for retransmission carriessecond control information, the second control information includesscheduling information of downlink data corresponding to the at leastone of the physical downlink control channel for retransmission, thedownlink data corresponding to the at least one of the physical downlinkcontrol channel for retransmission is sent by a second network device tothe user equipment, and the second network device is controlled by thefirst network device.

With reference to the fifth aspect or any one of the possibleimplementation manners of the fifth aspect, in a sixth possibleimplementation manner, the transmitter is further configured to: for thephysical downlink control channel in the at least one subset, notify theuser equipment of one group of common reference signal CRS rate matchinginformation, where at least one piece of CRS rate matching informationin the group of CRS rate matching information includes at least twopieces of CRS pattern information, and the at least one piece of CRSrate matching information in the group of CRS rate matching informationis used for rate matching for the downlink data indicated by thephysical downlink control channel in the at least one subset.

With reference to the fifth aspect or any one of the possibleimplementation manners of the fifth aspect, in a seventh possibleimplementation manner, the information about the first resource setgroup sent by the transmitter includes time-frequency resourceconfiguration information of the physical downlink control channel set,and/or the information about the second resource set group sent by thetransmitter includes time-frequency resource configuration informationof the physical downlink control channel for retransmission.

According to a sixth aspect, user equipment is provided, including:

-   -   a memory, configured to: store information that is about a first        resource set group of a physical downlink control channel set        and sent by a first network device to the user equipment in        advance, and store information that is about a second resource        set group of a physical downlink control channel for        retransmission and sent by the first network device to the user        equipment in advance;    -   a receiver, configured to: receive at least one physical        downlink control channel according to the information that is        about the first resource set group and stored by the memory,        acquire first control information carried on the at least one        physical downlink control channel, and receive downlink data        according to scheduling information that is of the downlink data        and included in the first control information, where the at        least one physical downlink control channel is a physical        downlink control channel in at least one subset of the physical        downlink control channel set; and    -   a processor, configured to detect, in the second resource set        group corresponding to the information that is about the second        resource set group and stored by the memory, the physical        downlink control channel for retransmission corresponding to the        downlink data.

With reference to the sixth aspect, in a first possible implementationmanner, the information that is about the second resource set group andstored by the memory includes a correspondence, and the correspondenceis a correspondence between the physical downlink control channel in theat least one subset and the second resource set group, or thecorrespondence is a correspondence between a subset of the physicaldownlink control channel set and the second resource set group; and

-   -   the processor is further configured to: before detecting, in the        second resource set group, the physical downlink control channel        for retransmission corresponding to the downlink data,        determine, according to the correspondence stored by the memory        and the at least one physical downlink control channel received        by the receiver, the second resource set group corresponding to        retransmission of the downlink data.

With reference to the sixth aspect, in a second possible implementationmanner, the processor is further configured to determine, according toan indication in the at least one physical downlink control channelreceived by the receiver, the second resource set group corresponding toretransmission of the downlink data.

With reference to the sixth aspect or either of the possibleimplementation manners of the sixth aspect, in a third possibleimplementation manner, the receiver is further configured to: for thephysical downlink control channel in the at least one subset, receiveconfiguration information that is of a physical uplink control channeland notified by the first network device; the processor is furtherconfigured to: after the receiver receives the downlink data accordingto the scheduling information that is of the downlink data and includedin the first control information, determine, according to theconfiguration information that is of the physical uplink control channeland acquired by the receiver, resource information of the physicaluplink control channel corresponding to the downlink data; and the userequipment further includes a transmitter, configured to sendacknowledgement information of the downlink data according to theresource information that is of the physical uplink control channel anddetermined by the processor.

With reference to the third possible implementation manner of the sixthaspect, in a fourth possible implementation manner, the receiver isfurther configured to: if the acknowledgement information sent by thetransmitter is negative acknowledgement information, receive, accordingto the information about the second resource set group, at least one ofthe physical downlink control channel that is for retransmission and inthe second resource set group, where the physical downlink controlchannel for retransmission carries second control information; andreceive retransmitted downlink data according to scheduling informationincluded in the second control information, where the schedulinginformation is scheduling information of the downlink data correspondingto the physical downlink control channel for retransmission.

With reference to the third possible implementation manner or the fourthpossible implementation manner of the sixth aspect, in a fifth possibleimplementation manner, the receiver is further configured to: for thephysical downlink control channel in the at least one subset, receivetransmit power configuration information that is of the physical uplinkcontrol channel and notified by the first network device; and thetransmitter is specifically configured to send, in the following manner,the acknowledgement information of the downlink data according to theresource information that is of the physical uplink control channel anddetermined by the processor: determining transmit power information ofthe physical uplink control channel according to the transmit powerconfiguration information received by the receiver, and sending theacknowledgement information of the downlink data according to theresource information and the transmit power information of the physicaluplink control channel.

With reference to the fifth possible implementation manner of the sixthaspect, in a sixth possible implementation manner, the transmit powerconfiguration information received by the receiver includes referencesignal power; and the transmitter is specifically configured to: in thefollowing manner, determine the transmit power information of thephysical uplink control channel according to the transmit powerconfiguration information acquired by the receiver, and send theacknowledgement information of the downlink data according to theresource information and the transmit power information of the physicaluplink control channel: determining a downlink path loss estimateaccording to the reference signal power, determining transmit power ofthe physical uplink control channel according to the downlink path lossestimate, and sending the acknowledgement information of the downlinkdata according to the resource information and the transmit power of thephysical uplink control channel.

With reference to the sixth aspect or any one of the possibleimplementation manners of the sixth aspect, in a seventh possibleimplementation manner, the receiver is further configured to: for thephysical downlink control channel in the at least one subset, receiveone group of common reference signal CRS rate matching informationnotified by the first network device, where at least one piece of CRSrate matching information in the group of CRS rate matching informationincludes at least two pieces of CRS pattern information; and thereceiver is further configured to: before receiving the downlink data,perform, by using the at least one piece of CRS rate matchinginformation in the group of CRS rate matching information, rate matchingon the downlink data indicated by the physical downlink control channelin the at least one subset.

According to a seventh aspect, a data transmission system is provided,including a first network device and a second network device, where thefirst network device is configured to: send a transmission resourceparameter to the second network device, and transmit downlink data touser equipment by using the transmission resource parameter;

-   -   the second network device is configured to transmit the downlink        data to the user equipment by using the transmission resource        parameter sent by the first network device; and    -   the first network device is further configured to:    -   notify the user equipment of configuration information of an        uplink control channel resource, where the configuration        information of the uplink control channel resource is used to        indicate, for the user equipment, resource configuration        information for sending acknowledgement information        corresponding to the downlink data; and    -   receive the acknowledgement information, or instruct the second        network device to receive the acknowledgement information.

In a first possible implementation manner of the seventh aspect, if thefirst network device is further configured to receive theacknowledgement information, and when the acknowledgement information isa negative acknowledgement, the first network device is furtherconfigured to retransmit the downlink data to the user equipment;

-   -   or,    -   if the first network device is further configured to instruct        the second network device to receive the acknowledgement        information, and when the acknowledgement information is a        negative acknowledgement, the second network device is further        configured to retransmit the downlink data to the user        equipment.

With reference to the seventh aspect or the first possibleimplementation manner of the seventh aspect, in a second possibleimplementation manner, the first network device is specificallyconfigured to instruct, in the following manner, the second networkdevice to receive the acknowledgement information:

-   -   notifying, by the first network device, the second network        device of the configuration information of the uplink control        channel resource that carries the acknowledgement information.

With reference to the seventh aspect or either of the possibleimplementation manners of the seventh aspect, in a third possibleimplementation manner, the second network device is further configuredto receive one group of common reference signal CRS rate matchinginformation sent by the first network device; and

-   -   the first network device is further configured to: before        transmitting the downlink data to the user equipment by using        the transmission resource parameter, determine, from the group        of CRS rate matching information, CRS information corresponding        to transmission of the downlink data, and perform rate matching        by using the determined CRS information; or    -   the second network device is further configured to: before        transmitting the downlink data to the user equipment by using        the transmission resource parameter, determine, from the group        of CRS rate matching information, CRS information corresponding        to transmission of the downlink data, and perform rate matching        by using the determined CRS information.

With reference to the seventh aspect or any one of the possibleimplementation manners of the seventh aspect, in a fourth possibleimplementation manner, the transmission resource parameter sent by thefirst network device includes at least one of a physical resource usedfor transmitting the downlink data, a modulation and coding manner, adata block size, a time at which a data block is sent, and a hybridautomatic repeat request process number each time a data block is sent.

According to an eighth aspect, a data transmission system is provided,including a first network device, a second network device, and a thirdnetwork device; where

-   -   the first network device is configured to send a transmission        resource parameter to the second network device and/or the third        network device;    -   the second network device is configured to transmit downlink        data to user equipment by using the transmission resource        parameter sent by the first network device; and/or    -   the third network device is configured to transmit the downlink        data to the user equipment by using the transmission resource        parameter sent by the first network device; and    -   the first network device is further configured to:    -   notify the user equipment of configuration information of an        uplink control channel resource, where the configuration        information of the uplink control channel resource is used to        indicate, for the user equipment, resource configuration        information for sending acknowledgement information        corresponding to the downlink data; and    -   receive the acknowledgement information, or instruct the second        network device or the third network device to receive the        acknowledgement information.

In a first possible implementation manner of the eighth aspect, if thefirst network device is further configured to receive theacknowledgement information, and when the acknowledgement information isa negative acknowledgement, the first network device is furtherconfigured to retransmit the downlink data to the user equipment;

-   -   or,    -   if the first network device is further configured to instruct        the second network device to receive the acknowledgement        information, and when the acknowledgement information is a        negative acknowledgement, the second network device is further        configured to retransmit the downlink data to the user        equipment;    -   or,    -   if the first network device is further configured to instruct        the third network device to receive the acknowledgement        information, and when the acknowledgement information is a        negative acknowledgement, the third network device is further        configured to retransmit the downlink data to the user        equipment.

With reference to the eighth aspect or the first possible implementationmanner of the eighth aspect, in a second possible implementation manner,the first network device is specifically configured to instruct, in thefollowing manner, the second network device or the third network deviceto receive the acknowledgement information:

-   -   notifying, by the first network device, the second network        device or the third network device of the configuration        information of the uplink control channel resource that carries        the acknowledgement information.

With reference to the eighth aspect or either of the possibleimplementation manners of the eighth aspect, in a third possibleimplementation manner, the first network device is further configured tonotify the second network device and the third network device of onegroup of CRS rate matching information; and

-   -   the second network device is further configured to: before        transmitting the downlink data to the user equipment by using        the transmission resource parameter sent by the first network        device, determine, by using the group of CRS rate matching        information, CRS information corresponding to transmission of        the downlink data, and perform rate matching by using the        determined CRS information; or    -   the third network device is further configured to: before        transmitting the downlink data to the user equipment by using        the transmission resource parameter sent by the first network        device, determine, by using the group of CRS rate matching        information, CRS information corresponding to transmission of        the downlink data, and perform rate matching by using the        determined CRS information.

With reference to the eighth aspect or any one of the possibleimplementation manners of the eighth aspect, in a fourth possibleimplementation manner, the transmission resource parameter informationsent by the first network device includes at least one of a physicalresource used for transmitting the downlink data, a modulation andcoding manner, a data block size, a time at which a data block is sent,and a hybrid automatic repeat request HARQ process number each time adata block is sent.

In the foregoing solution, a network device separately configures, foruser equipment, a first resource set group of a physical downlinkcontrol channel set and a second resource set group of a physicalcontrol channel for retransmission, where the physical control channelfor retransmission is a physical control channel for retransmissioncorresponding to downlink data indicated by a physical control channelin at least one subset of the physical control channel set, so that theUE can detect, in the preconfigured first resource set group and secondresource set group, a physical downlink control channel used for initialtransmission and the physical downlink control channel used forretransmission. In this way, in an HARQ process, the UE can obtain acoordination gain of multiple resources by using multiple preconfiguredtransmission resources (including resources in the first resource setgroup and the second resource set group). Therefore, in the embodimentsof the present invention, a coordination gain can still be implementedonly with a need of semi-static configuration and without a need ofquick information exchange. In addition, the network device separatelypreconfigures, for the user equipment, the first resource set group thatis of the physical downlink control channel set and used for initialtransmission and the second resource set group used for retransmission,which reduces complexity of blind detection, which the UE performs whenobtaining a coordination gain, on the physical downlink control channelfor retransmission.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an optional application scenario of an embodiment of aninformation configuration method and a data receiving method accordingto the present invention;

FIG. 2 is a schematic flowchart of an embodiment of an informationconfiguration method according to the present invention;

FIG. 2a is a schematic flowchart of another embodiment of an informationconfiguration method according to the present invention;

FIG. 3 is a schematic flowchart of an embodiment of a data receivingmethod according to the present invention;

FIG. 4 is a schematic flowchart of an embodiment of a data transmissionmethod according to the present invention;

FIG. 5 is a schematic flowchart of another embodiment of a datatransmission method according to the present invention;

FIG. 6 is a schematic signaling diagram of another embodiment of aninformation configuration method according to the present invention;

FIG. 7 is a schematic structural diagram of an embodiment of a networkdevice according to the present invention;

FIG. 8 is a schematic structural diagram of another embodiment of anetwork device according to the present invention;

FIG. 9 is a schematic structural diagram of an embodiment of userequipment according to the present invention;

FIG. 10 is a schematic structural diagram of another embodiment of userequipment according to the present invention;

FIG. 11 is a schematic diagram of a physical structure of an embodimentof a network device according to the present invention;

FIG. 12 is a schematic diagram of a physical structure of anotherembodiment of a network device according to the present invention;

FIG. 13 is a schematic diagram of a physical structure of an embodimentof user equipment according to the present invention;

FIG. 14 is a schematic diagram of a physical structure of anotherembodiment of user equipment according to the present invention;

FIG. 15 is a schematic structural diagram of an embodiment of a datatransmission system according to the present invention; and

FIG. 16 is a schematic structural diagram of another embodiment of adata transmission system according to the present invention.

DESCRIPTION OF EMBODIMENTS

FIG. 1 is an optional application scenario of an embodiment of aninformation configuration method and a data receiving method accordingto the present invention. As shown in FIG. 1, a base station 0 and abase station 1 jointly transmit data to UE to enhance signal receivingquality of the UE; in addition, when the UE fails to receive the data,either of the base station 0 and the base station 1 is responsible forretransmitting the data to the UE. Certainly, during specificimplementation, the methods in the embodiments of the present inventionare not limited to the application scenario shown in FIG. 1, and thereare not always two base stations. The following describes theinformation configuration method or the data receiving method in theembodiments of the present invention.

In a non-ideal backhaul scenario, there is a relatively large delay forinformation exchange between multiple network devices; therefore, anetwork device is likely fail to learn a data sending status of anothernetwork device in a timely manner, for example, fails to learn whetherdata sent by another network device is correctly received by UE.Therefore, a dynamic retransmission solution in an ideal backhaulscenario cannot be used, and in the non-ideal backhaul scenario, acoordination gain cannot be obtained by means of coordination betweenmultiple network devices in an aspect of data transmission. In addition,for a same network device, the network device may perform coordinationin an aspect of data transmission by means of quick information exchangebetween multiple modules in the network device, so that a coordinationgain is obtained. However, the solution to implementing quickinformation exchange between multiple modules is relatively complex. Thefollowing methods in the embodiments of the present invention describehow multiple transmission points implement a coordination gain by usingthe methods.

It should be noted that the embodiments of the present invention may becombined with each other in a case in which no conflict exists.

Embodiment 1

FIG. 2 is a schematic flowchart of an embodiment of an informationconfiguration method according to the present invention. As shown inFIG. 2, the method may include the following steps.

201. A first network device configures a first resource set group of aphysical downlink control channel set for user equipment, andconfigures, for the user equipment, a second resource set group of aphysical downlink control channel for retransmission, where the physicaldownlink control channel for retransmission is a physical downlinkcontrol channel for retransmission corresponding to downlink dataindicated by a physical downlink control channel in at least one subsetof the physical downlink control channel set.

202. The first network device sends information about the first resourceset group and information about the second resource set group to theuser equipment.

In the foregoing embodiment, a network device separately configures, foruser equipment, a first resource set group of a physical downlinkcontrol channel set and a second resource set group of a physicalcontrol channel for retransmission, where the physical control channelfor retransmission is a physical control channel for retransmissioncorresponding to downlink data indicated by a physical control channelin at least one subset of the physical control channel set, so that theUE can detect, in the preconfigured first resource set group and secondresource set group, a physical downlink control channel used for initialtransmission and the physical downlink control channel used forretransmission. In this way, in an HARQ process, the UE can obtain acoordination gain of multiple resources by using multiple preconfiguredtransmission resources (including resources in the first resource setgroup and the second resource set group). Therefore, in this embodimentof the present invention, a coordination gain can still be implementedonly with a need of semi-static configuration and without a need ofquick information exchange. In addition, the network device separatelypreconfigures, for the user equipment, the first resource set group thatis of the physical downlink control channel set and used for initialtransmission and the second resource set group used for retransmission,which reduces complexity of blind detection, which the UE performs whenobtaining a coordination gain, on the physical downlink control channelfor retransmission.

It should be noted that this embodiment of the present invention isdescribed by using a first network device and a second network device asexamples; however, this embodiment of the present invention may beapplied to a case of only one network device, for example, a case inwhich there is only a first network device. In this case, a first moduleand a second module in the network device perform correspondingprocessing, for which reference is made to descriptions in thisembodiment of the present invention. For brevity, details are notdescribed again.

In the foregoing embodiment, the first network device, such as a basestation 0 or a base station 1 shown in FIG. 1, is a device responsiblefor configuring the first resource set group of the physical downlinkcontrol channel set for the user equipment (UE for short), and may be,or may not be a device responsible for transmitting downlink data to theUE. However, during specific implementation, alternatively, the firstnetwork device may be another type of network device except the basestation. The first resource set group includes a resource of a physicaldownlink control channel set corresponding toto-be-initially-transmitted downlink data.

In an example of this step, the base station 0 may send the informationabout the first resource set group. For example, the base station 0notifies the UE of the semi-static information of the first resource setgroup by using higher layer signaling, so that the first resource setgroup is preconfigured for the UE. Certainly, in a specific embodiment,alternatively, the base station 1 may perform the sending, and the like.In this case, the base station 1 is a device responsible for configuringthe first resource set group of the physical downlink control channelset for the UE.

The physical downlink control channel set includes a physical downlinkcontrol channel that may be used for the to-be-initially-transmitteddownlink data.

The information about the first resource set group may be resource setinformation required by the UE for detecting a physical downlink controlchannel in the physical downlink control channel set. For example, theinformation about the first resource set group may includetime-frequency resource configuration information of the physicaldownlink control channel set corresponding to theto-be-initially-transmitted downlink data, and the physical downlinkcontrol channel in the physical downlink control channel set may be aphysical downlink control channel (PDCCH for short) or an enhancedphysical downlink control channel (EPDCCH for short). One resource setgroup may include one or more resource sets, and therefore, is referredto as one group. One resource set may include time-frequency resourcesused by the one or more physical downlink control channels. For example,one resource set corresponding to an EPDCCH may include one or morephysical resource blocks or physical resource block pairs (PRB Pair forshort), and one physical resource block pair includes two physicalresource blocks in one subframe. Information about one resource set mayinclude a time-frequency resource and/or a scrambling code used by aphysical downlink control channel corresponding to the set. Scramblingcodes of physical downlink control channels corresponding to differentresource sets may be different. The UE may detect the physical downlinkcontrol channel in the physical downlink control channel set accordingto the information about the first resource set group, so as toimplement receiving of control information corresponding to downlinkdata.

The physical downlink control channel for retransmission is a physicaldownlink control channel used for retransmission. For example, the basestation 0 may notify the UE of the information about the second resourceset group by using higher-layer signaling. In this case, according tothe information about the second resource set group, the UE may detect,on resources in the preconfigured second resource set group, thephysical downlink control channel for retransmission, for example,detect all candidate physical downlink control channels of the UE.Certainly, in a specific embodiment, alternatively, the base station 1may perform the sending, and the like.

The information about the second resource set group may includetime-frequency resource configuration information of the physicaldownlink control channel corresponding to retransmission of the downlinkdata, where the physical downlink control channel may be a PDCCH or anEPDCCH. The UE may detect, according to the information about the secondresource set group, the physical downlink control channel forretransmission, for example, detect the candidate physical downlinkcontrol channel of the UE. In a specific embodiment, the second resourceset group may be included in the first resource set group, that is, thesecond resource set group may be a subset of the first resource setgroup. Alternatively, the second resource set group may intersect withthe first resource set group, or the second resource set group and thefirst resource set group may be mutually independent resource sets, thatis, the second resource set group does not intersect with the firstresource set group.

Optionally, in an embodiment, the following may be further included: Theinformation about the second resource set group may include acorrespondence, and the correspondence is a correspondence between thephysical downlink control channel in the at least one subset and thesecond resource set group or a correspondence between the at least onesubset and the second resource set group. In this case, aftersubsequently receiving at least one physical downlink control channel inthe at least one subset of the physical downlink control channel set,the UE may determine the second resource set group according to thecorrespondence and the at least one received physical downlink controlchannel.

Optionally, information about the correspondence may include a cellradio network temporary identifier (C-RNTI for short) used by thephysical downlink control channel in the at least one subset. The atleast one subset is determined according to information about the cellradio network temporary identifier. That is, a subset formed by thephysical downlink control channel that is in the physical downlinkcontrol channel set and has the C-RNTI is corresponding to the secondresource set group. The C-RNTI is identification information of 16 bitsthat is scrambled in a cyclic redundancy code (CRC for short) of 16bits. In this case, the UE may detect a physical downlink controlchannel on a resource in the first resource set group by using theC-RNTI. At an assumption that a physical downlink control channel thatbelongs to the UE is detected by using the C-RNTI, the UE may determine,according to the correspondence and the received physical downlinkcontrol channel, that the physical downlink control channel forretransmission corresponding to retransmission of the downlink data isin the second resource set group. At an assumption that a physicaldownlink control channel that belongs to the UE is detected not by usingthis C-RNTI, but by using another C-RNTI, the UE may determine that thecontrol channel corresponding to retransmission of the downlink data isnot in the second resource set group of the physical downlink controlchannel for retransmission, and may still be in the first resource setgroup of the physical downlink control channel set.

Optionally, in another embodiment, in addition to the C-RNTI used by thephysical downlink control channel in the at least one subset, thecorrespondence of which the UE is notified may further include adownlink control information (DCI for short) format used by the physicaldownlink control channel in the at least one subset, a scrambling codeused by the physical downlink control channel, and the like. That is,the at least one subset is determined by using the method, and the atleast one subset is corresponding to the second resource set group.

Optionally, the physical downlink control channel in the at least onesubset further indicates the second resource set group. For example, bitinformation in the DCI of the physical downlink control channel ispredefined to indicate whether the control channel for retransmissionbelongs to the first resource set or the second resource set group, thatis, the DCI includes resource set indication information.

Optionally, for the physical downlink control channel in the at leastone subset, the first network device may further notify the userequipment of configuration information of a physical uplink controlchannel and/or transmit power configuration information of the physicaluplink control channel, where the physical uplink control channel isused to carry acknowledgement information of the downlink data indicatedby the physical downlink control channel. This step may be executedbefore or after any step in this embodiment. The at least one subset maybe determined by using a specific C-RNTI. That is, the first networkdevice may notify a specific C-RNTI to determine at least one subset,that is, a physical downlink control channel that is in the physicaldownlink control channel set and has the C-RNTI forms the at least onesubset.

The transmit power configuration information of the configurationinformation of the physical uplink control channel is used by the UE todetermine resource information of the corresponding physical uplinkcontrol channel that carries the to-be-initially-transmitted downlinkdata, the transmit power configuration information of the physicaluplink control channel is used by the UE to determine transmit powerinformation of the physical uplink control channel, and the physicaluplink control channel is used to carry the acknowledgement information.For example, the configuration information of the physical uplinkcontrol channel may include resource configuration information of aphysical uplink shared channel (PUSCH for short) that carries an uplinkcontrol information (UCI for short) or a physical uplink control channel(PUCCH for short). At an assumption that the base station 1 receives theacknowledgement information and is responsible for retransmission, thebase station 0 may also notify the base station 1 of the resourceconfiguration information of the PUSCH that carries the UCI or thePUCCH, so that the base station 1 receives the acknowledgementinformation according to the resource configuration information. Foranother example, the transmit power configuration information of thephysical uplink control channel may include power configurationinformation of the PUSCH that carries the UCI or the PUCCH, so that theUE sends the acknowledgement information according to the transmit powerconfiguration information.

Further, the foregoing embodiment may further include the followingstep:

Optionally, for the physical downlink control channel in the at leastone subset, the network device further notifies the user equipment ofthe transmit power configuration information of the physical uplinkcontrol channel. For example, the base station 0 notifies the UE of thetransmit power configuration information of the physical uplink controlchannel by using higher layer signaling. Certainly, in a specificembodiment, alternatively, the base station 1 may perform the sending,and the like. This embodiment imposes no limitation on an executionsequence between this step and other steps. For example, the transmitpower configuration information of the physical uplink control channelmay be sent when the configuration information of the physical uplinkcontrol channel is sent, or may be sent before or after theconfiguration information of the physical uplink control channel issent.

Optionally, the configuration information of the physical uplink controlchannel may also be used by the UE to determine a base station to whichthe acknowledgement information is to be fed back or a base station thatreceives the resource information, or may be used by the UE to determinea base station responsible for retransmission.

Optionally, for the physical downlink control channel in the at leastone subset, the network device notifies the user equipment of one groupof common reference signal (CRS for short) rate matching information,and at least one piece of CRS rate matching information in the group ofCRS rate matching information includes at least two pieces of CRSpattern information.

There is a correspondence between the group of CRS rate matchinginformation and the physical downlink control channel set, that is, thegroup of CRS rate matching information is corresponding to the downlinkdata indicated by the at least one physical downlink control channelreceived by the UE, so that the UE implements receiving of the downlinkdata. One group of CRS rate matching information may include one or morepieces of CRS rate matching information. One piece of CRS rate matchinginformation may indicate one or more pieces of CRS pattern information.A piece of CRS rate matching information of a downlink data channel maybe used for resource mapping of a data channel, so that a resourceelement occupied by an indicated CRS pattern is not used for resourcemapping of the data channel. When the group of CRS rate matchinginformation corresponding to the physical downlink control channelincludes multiple pieces of CRS rate matching information, a piece ofCRS rate matching information used for a data channel may be indicatedin the physical downlink control channel, for example, is indicated in abit field of a physical downlink shared channel resource element mappingand quasi-co-location indicator PQI (PDSCH RE mapping andQuasi-co-location Indicator) on the physical downlink control channel.At least one piece of CRS rate matching information in the group of CRSrate matching information is used for rate matching for the downlinkdata indicated by the physical downlink control channel in the at leastone subset.

It should be noted that the CRS rate matching information includes, forexample, CRS information used to indicate a CRS pattern. For example, atleast one piece of CRS rate matching information of one group of CRSrate matching information includes at least two pieces of CRS patterninformation. In addition, at an assumption that as shown in FIG. 1, thebase station 0 and the base station 1 jointly transmit data to the UE,the piece of CRS rate matching information may include, for example, CRSinformation respectively corresponding to the two devices, that is, thebase station 0 and the base station 1. For another example, if the UEfails to receive data, at an assumption that the base station 0 needs toretransmit the data to the UE, the piece of CRS rate matchinginformation may include CRS information corresponding to the basestation 0.

According to the information configuration method in this embodiment ofthe present invention, a first network device separately configures, foruser equipment, a first resource set group that is of a physicaldownlink control channel set and used for initial transmission and asecond resource set group used for retransmission, so that the UE candetect, in the preconfigured first resource set group and secondresource set group, a physical downlink control channel used for initialtransmission and a physical downlink control channel used forretransmission. In this way, in a hybrid automatic repeat request(Hybrid Automatic Repeat Request, HARQ for short) process, the UE canobtain a coordination gain of multiple resources by using multiplepreconfigured transmission resources (including resources in the firstresource set group and the second resource set group). In addition, thefirst network device separately preconfigures, for the user equipment,the first resource set group that is of the physical downlink controlchannel set and used for initial transmission and the second resourceset group used for retransmission, which reduces complexity of blinddetection, which the UE performs when obtaining a coordination gain, onthe physical downlink control channel for retransmission.

Optionally, as shown in FIG. 2a , Embodiment 1 described above mayfurther include the following step:

203. The first network device sends at least one physical downlinkcontrol channel of the physical downlink control channel in the at leastone subset to the user equipment, where the at least one physicaldownlink control channel carries first control information, and thefirst control information includes scheduling information of thedownlink data; and/or

a second network device sends at least one physical downlink controlchannel of the physical downlink control channel in the at least onesubset to the user equipment, where the at least one physical downlinkcontrol channel carries first control information, the first controlinformation includes scheduling information of the downlink data, andthe second network device is controlled by the first network device.

In this step, at least one of the first network device and the secondnetwork device may send the physical downlink control channel to theuser equipment, so that the downlink data is transmitted to the userequipment. In this case, the user equipment can receive the data fromthe at least one network device by using the preconfigured firstresource set group.

For example, if the foregoing step is executed by the base station 0, inthis step, the base station 0 may send, to the UE, the at least onephysical downlink control channel in the at least one subset of thephysical downlink control channel set in the first resource set group,and the UE may receive, on the physical downlink control channel, thefirst control information corresponding to the downlink data, where thefirst control information includes the scheduling information of thedownlink data. Alternatively, if the foregoing step is executed by thebase station 1, in this step, the base station 1 may send, to the UE,the at least one physical downlink control channel in the at least onesubset of the physical downlink control channel set in the firstresource set group. Alternatively, if the foregoing step is executed byboth the base station 0 and the base station 1, in this step, the basestation 0 and the base station 1 may send, to the UE, the at least onephysical downlink control channel in the at least one subset of thephysical downlink control channel set in the first resource set group.When the foregoing step is executed by both the base station 0 and thebase station 1, the base station 0 and the base station 1 need to use asame transmission manner of the physical downlink control channel andcarry same DCI, so as to perform transmission, where the sametransmission manner and the same DCI are coordinated in advance. Afterthis step, the UE may receive, according to the at least one receivedphysical downlink control channel, the initially transmitted downlinkdata.

Specifically, the scheduling information of the downlink data mayinclude one or more of downlink data resource configuration information,modulation and coding manner information, and an HARQ process number. Ina specific embodiment, as described in step 202, the schedulinginformation of the downlink data may further include resource setindication information, and the UE may determine the second resource setgroup according to the resource set indication information.

In addition, after the first network device notifies the UE of the CRSrate matching information, the first network device may perform,according to the CRS rate matching information by using the at least onepiece of CRS rate matching information in the group of CRS rate matchinginformation, rate matching on the downlink data indicated by thephysical downlink control channel in the at least one subset, and thentransmit the downlink data to the user equipment. For example, if thefirst network device is one of at least two devices that jointlytransmit data, the first network device delivers information about thefirst resource set group to the UE, the first network device deliversthe group of CRS rate matching information to the UE, and the secondnetwork device and the first network device jointly transmit thedownlink data to the UE. The second network device refers to anothernetwork device that transmits data together with the first networkdevice, and this embodiment imposes no limitation on a quantity ofsecond network devices.

For example, in the scenario, shown in FIG. 1, in which the base station0 and the base station 1 jointly transmit data to the UE, the basestation 0 may notify the UE of one group of CRS rate matchinginformation, where the group of CRS rate matching information includesCRS information respectively corresponding to the base station 0 and thebase station 1; in addition, the base station 0 and the base station 1transmit the downlink data to the UE according to the group of CRS ratematching information, and the UE receives the downlink data according tothe group of received CRS rate matching information.

By using this step, it can be implemented that in a non-ideal backhaulcase, for initial transmission, data may be sent to the UE in acoordinated manner, so that reliability of data sending is higher.

Optionally, Embodiment 1 described above may further include thefollowing step:

204. After the first network device sends the at least one physicaldownlink control channel of the physical downlink control channel in theat least one subset to the user equipment, the following is furtherincluded: If the second network device receives negative acknowledgementinformation sent by the user equipment, the second network device sends,to the user equipment, at least one of the physical downlink controlchannel that is for retransmission and in the second resource set group,where the at least one of the physical downlink control channel forretransmission carries second control information, and the secondcontrol information includes scheduling information of downlink datacorresponding to the at least one of the physical downlink controlchannel for retransmission; or

after the second network device sends the at least one physical downlinkcontrol channel of the physical downlink control channel in the at leastone subset to the user equipment, the following is further included: ifthe first network device receives negative acknowledgement informationsent by the user equipment, the first network device sends, to the userequipment, the at least one of the physical downlink control channelthat is for retransmission and in the second resource set group, wherethe at least one of the physical downlink control channel forretransmission carries second control information, and the secondcontrol information includes scheduling information of downlink datacorresponding to the at least one of the physical downlink controlchannel for retransmission.

In this step, after receiving the configuration information of thephysical uplink control channel, UE may send acknowledgement informationon a corresponding resource. The first network device or the secondnetwork device receives the acknowledgement information on thecorresponding resource. Therefore, it can be implemented that ifdownlink data is sent by the first network device, the second networkdevice may implement retransmission (that is, the second network devicereceives the NACK), and vice versa, or if downlink data is sent by thefirst network device and the second network device together, any networkdevice that receives the NACK may implement retransmission. Therefore,the first network device or the second network device can perform dataretransmission according to a preconfiguration, instead of performingcoordination in an aspect of data transmission with quick informationexchange.

It should be noted that in this embodiment of the present invention,configurations such as the first resource set group, the second resourceset group, the transmit power configuration information of the physicaluplink control channel, the transmit power configuration information ofthe physical uplink control channel, and the group of CRS rate matchinginformation may change. If a change occurs, configuration is performedagain according to the method in this embodiment of the presentinvention. For example, if the second resource set group changes, thefirst network device sends, to the user equipment, changed informationabout the second resource set group. A case for the first resource setgroup is similar to that for the second resource set group.

Embodiment 2

FIG. 3 is a schematic flowchart of an embodiment of a data receivingmethod according to the present invention. The method may be executed byuser equipment. It should be noted that for specific descriptions ofsame content in this embodiment as that in Embodiment 1, reference maybe made to descriptions in Embodiment 1, and this embodiment gives onlybrief descriptions. As shown in FIG. 3, the method may include thefollowing steps:

301. User equipment receives at least one physical downlink controlchannel according to information about a first resource set group sentby a first network device, acquires first control information carried onthe at least one physical downlink control channel, and receivesdownlink data according to scheduling information that is of thedownlink data and included in the first control information, where thefirst resource set group is a resource set that is of a physicaldownlink control channel set and preconfigured by the first networkdevice for the user equipment, and the at least one physical downlinkcontrol channel is a physical downlink control channel in at least onesubset of the physical downlink control channel set.

In this step, with reference to a scenario shown in FIG. 1, the at leastone physical downlink control channel received by the user equipment maybe sent, for example, by a base station 0, or by a base station 1, or bya base station 0 and a base station 1. The scheduling information of thedownlink data may include one or more of downlink data resourceconfiguration information, modulation and coding manner information, andan HARQ process number, and is used by the user equipment to receive thedownlink data.

Further, before the user equipment receives the downlink data accordingto the scheduling information that is of the downlink data and includedin the first control information, for the physical downlink controlchannel in the at least one subset, the user equipment further receivesone group of common reference signal CRS rate matching informationnotified by the first network device, where at least one piece of CRSrate matching information in the group of CRS rate matching informationincludes at least two pieces of CRS pattern information. In this case,the user equipment may perform, by using the at least one piece of CRSrate matching information in the group of CRS rate matching information,rate matching on the downlink data indicated by the physical downlinkcontrol channel in the at least one subset, and then receive thedownlink data. A piece of CRS rate matching information of a downlinkdata channel may be used for resource mapping of a data channel, so thata resource element occupied by an indicated CRS pattern is not used forresource mapping of the data channel.

302. The user equipment detects, in a second resource set groupcorresponding to information about the second resource set group sent bythe first network device, a physical downlink control channel forretransmission corresponding to the downlink data, where the secondresource set group is a resource set that is of the physical downlinkcontrol channel for retransmission and preconfigured by the firstnetwork device for the user equipment.

The second resource set group is a resource set that is of the physicaldownlink control channel for retransmission and preconfigured by thefirst network device for the user equipment. For example, in thisembodiment, both the information that is about the first resource setgroup and received by the user equipment in step 301 and the informationabout the second resource set group in this step may be sent by thefirst network device. For example, with reference to the scenario shownin FIG. 1, the information about the first resource set group and theinformation about the second resource set group may be sent by the basestation 0 or the base station 1 to the user equipment, or certainly, maybe sent by another device.

Further, before detecting, in the second resource set group, thephysical downlink control channel for retransmission corresponding tothe downlink data, the user equipment needs to determine, according tothe at least one received physical downlink control channel and acorrespondence, the second resource set group corresponding toretransmission of the downlink data, where the correspondence isincluded in the information about the second resource set group, and isa correspondence between the physical downlink control channel in the atleast one subset and the second resource set group, or thecorrespondence is a correspondence between the subset of the physicaldownlink control channel set and the second resource set group. The userequipment may determine, according to the correspondence and the atleast one received physical downlink control channel, the secondresource set group corresponding to the retransmission of the downlinkdata.

Optionally, the user equipment may determine, according to an indicationin the at least one received physical downlink control channel, thesecond resource set group corresponding to retransmission of thedownlink data.

Further, for the physical downlink control channel in the at least onesubset, the user equipment further receives configuration informationthat is of a physical uplink control channel and notified by the firstnetwork device. After the user equipment receives the downlink dataaccording to the scheduling information of the downlink data, the userequipment determines, according to the configuration information of thephysical uplink control channel, resource information of the physicaluplink control channel corresponding to the downlink data, and sendsacknowledgement information of the downlink data according to theresource information of the physical uplink control channel.

For example, if the acknowledgement information is negativeacknowledgement information, the user equipment receives, according tothe information about the second resource set group, at least one of thephysical downlink control channel that is for retransmission and in thesecond resource set group, where the physical downlink control channelfor retransmission carries second control information.

The user equipment receives retransmitted downlink data according toscheduling information included in the second control information, wherethe scheduling information is scheduling information of the downlinkdata corresponding to the physical downlink control channel forretransmission. The retransmitted downlink data is retransmissioncorresponding to the downlink data indicated by the physical controlchannel in the at least one subset of the physical control channel set.

Optionally, before the user equipment sends the acknowledgementinformation of the downlink data according to the resource informationof the physical uplink control channel, for the physical downlinkcontrol channel in the at least one subset, the user equipment receivestransmit power configuration information that is of the physical uplinkcontrol channel and notified by the first network device. In this case,the user equipment determines transmit power information of the physicaluplink control channel according to the transmit power configurationinformation, and sends the acknowledgement information of the downlinkdata according to the resource information and the transmit powerinformation of the physical uplink control channel.

More specifically, the foregoing transmit power configurationinformation received by the user equipment may include reference signalpower. Specifically, the user equipment may determine a downlink pathloss estimate according to the reference signal power, determinetransmit power of the physical uplink control channel according to thedownlink path loss estimate, and send the acknowledgement information ofthe downlink data according to the resource information and the transmitpower of the physical uplink control channel.

In the foregoing embodiment, a network device separately configures, foruser equipment, a first resource set group of a physical downlinkcontrol channel set and a second resource set group of a physicalcontrol channel for retransmission, where the physical control channelfor retransmission is a physical control channel for retransmissioncorresponding to downlink data indicated by a physical control channelin at least one subset of the physical control channel set, so that theUE can detect, in the preconfigured first resource set group and secondresource set group, a physical downlink control channel used for initialtransmission and the physical downlink control channel used forretransmission. In this way, in an HARQ process, the UE can obtain acoordination gain of multiple resources by using multiple preconfiguredtransmission resources (including resources in the first resource setgroup and the second resource set group). Therefore, in this embodimentof the present invention, a coordination gain can still be implementedonly with a need of semi-static configuration and without a need ofquick information exchange. In addition, the network device separatelypreconfigures, for the user equipment, the first resource set group thatis of the physical downlink control channel set and used for initialtransmission and the second resource set group used for retransmission,which reduces complexity of blind detection, which the UE performs whenobtaining a coordination gain, on the physical downlink control channelfor retransmission.

Embodiment 3

FIG. 4 is a schematic flowchart of an embodiment of a data transmissionmethod according to the present invention. This embodiment provides adata transmission method, so that in a non-ideal backhaul scenario, atleast two network devices can send data to user equipment in acoordinated manner to obtain a coordination gain. It should be notedthat for descriptions of terms in this embodiment, reference may be madeto descriptions of the same terms in the foregoing embodiments, anddetails are not described again in this embodiment. This embodimentillustrates an exemplary scenario, as shown in a scenario in FIG. 1. Abase station 0 (which may be referred to as a first network device) anda base station 1 (which may be referred to as a second network device)jointly transmit downlink data to UE, and the base station 0 sends onegroup of CRS rate matching information to the UE, where the group of CRSrate matching information includes CRS information respectivelycorresponding to the base station 0 and the base station 1.

401. The first network device transmits downlink data to the userequipment by using a transmission resource parameter, and the secondnetwork device transmits the downlink data to the user equipment byusing the transmission resource parameter, where the transmissionresource parameter used by the second network device is configured bythe first network device for the second network device.

The transmission resource parameter in this embodiment may include atleast one of a physical resource used for transmitting the downlinkdata, a modulation and coding manner, a data block size, a time at whicha data block is sent, and an HARQ process number each time a data blockis sent. The first network device and the second network device may sendthe downlink data to the user equipment according to informationincluded in the transmission resource parameter.

Optionally, the downlink data may include data carried on a physicaldownlink shared channel and/or data carried on a physical downlinkcontrol channel.

Optionally, in this step, when transmitting the downlink data to theuser equipment by using the transmission resource parameter, the firstnetwork device and the second network device may specifically executethe following in the following manner:

-   -   transmitting, by the first network device and the second network        device, the downlink data to the user equipment according to CRS        rate matching information and the transmission resource        parameter, where the CRS rate matching information based on        which the second network device performs transmission is        preconfigured by the first network device for the second network        device, and for details, reference may be made to descriptions        in the foregoing embodiments.

Specifically, the scenario shown in FIG. 1 is used as an example. Thesystem includes two network devices that jointly transmit data to theUE, such as the base station 0 and the base station 1. The base station0 may be a main control base station, the base station 1 is a servingbase station, and the main control base station is responsible forcontrolling the two serving base stations.

When the at least two network devices jointly transmit the data to theUE, the at least two network devices transmit, at at least one subframe,the same downlink data to the UE by using same transmission resourceparameter information, so that the downlink data is jointly transmittedto the UE. Further, before the first network device and the secondnetwork device transmit, at the at least one subframe, the same downlinkdata to the user equipment by using the same transmission resourceparameter information, the method further includes: receiving, by thesecond network device, the transmission resource parameter informationnotified by the first network device. For example, the transmissionresource parameter information may be determined by the base station 0.In this case, there may be only the base station 0 and the base station1, the base station 0 is a main control base station, and the basestation 0 notifies the base station 1 of the transmission resourceparameter information in advance.

Certainly, in this embodiment, alternatively, the downlink data may betransmitted by only one of the first network device and the secondnetwork device to the UE.

402. The first network device receives acknowledgement information sentby the user equipment, or the first network device instructs the secondnetwork device to receive acknowledgement information, and the secondnetwork device receives the acknowledgement information sent by the userequipment, where the acknowledgement information is sent by the userequipment according to resource configuration information indicated byconfiguration information of a physical uplink control channel, and theconfiguration information of the physical uplink control channel isnotified by the first network device to the user equipment in advance.

The configuration information of the physical uplink control channel isused to indicate, for the user equipment, the resource configurationinformation for sending the acknowledgement information corresponding tothe downlink data.

In the foregoing solution, by means of interaction between the firstnetwork device and the second network device, in a non-ideal backhaulcase, for initial transmission, data may be sent to the UE in acoordinated manner, so that reliability of data sending is higher. Ifonly one of the first network device and the second network deviceperforms initial transmission, by using the method in this embodiment ofthe present invention, the first network device notifies the userequipment of configuration information of a physical uplink controlchannel in advance, and a transmission point for initial transmissionmay be different from a transmission point for retransmission.

Further, that the first network device instructs the second networkdevice to receive acknowledgement information may include: notifying, bythe first network device, the second network device of the configurationinformation of the uplink control channel resource that carries theacknowledgement information. For example, a main control base stationmay also separately notify the UE and a base station that is responsiblefor retransmission, such as the base station 1, of the configurationinformation of the uplink control channel resource that carries theacknowledgement information. In this case, the UE may send, according tothe configuration information, the acknowledgement informationcorresponding to the downlink data, and the base station 1 also knowsthat resource information of the acknowledgement informationcorresponding to the downlink data is to be received by the basestation 1. If the acknowledgement information fed back by the UE is aNACK, the base station 1 retransmits the downlink data to the UE.

403. If the first network device receives the acknowledgementinformation, and when the acknowledgement information is negativeacknowledgement information, the first network device retransmits thedownlink data to the user equipment; or if the second network devicereceives the acknowledgement information, and when the acknowledgementinformation is a negative acknowledgement, the second network deviceretransmits the downlink data to the user equipment.

Specifically, that the first network device retransmits the downlinkdata to the user equipment may include: if the first network devicereceives the negative acknowledgement information sent by the userequipment, sending, by the first network device to the user equipment,at least one physical downlink control channel for retransmission, wherethe at least one physical downlink control channel for retransmissioncarries second control information, and the second control informationincludes scheduling information of downlink data corresponding to the atleast one physical downlink control channel for retransmission; andretransmitting the downlink data to the user equipment according to thescheduling information; or similarly, that the second network deviceretransmits the downlink data to the user equipment may include: if thesecond network device receives the negative acknowledgement informationsent by the user equipment, sending, by the second network device to theuser equipment, at least one physical downlink control channel forretransmission, where the at least one physical downlink control channelfor retransmission carries second control information, and the secondcontrol information includes scheduling information of downlink datacorresponding to the at least one physical downlink control channel forretransmission.

If initial transmission is executed only by the first network device(that is, step 401), and retransmission is executed by the secondnetwork device (that is, step 403), the first network device configures,for the second network device, same downlink data initially transmittedby the first network device. The first network device knows a moment atwhich retransmission occurs; therefore, it is only required to ensurethat configuration is complete before retransmission occurs.

If initial transmission is executed only by the second network device(that is, step 401), and retransmission is executed by the first networkdevice (that is, step 403), because the first network device is a maincontrol network device, the first network device knows downlink datainitially transmitted by the second network device. Therefore, in thiscase, the first network device can implement retransmission.

Optionally, before the first network device and the second networkdevice transmit, at the at least one subframe, the same downlink data tothe user equipment by using the same transmission resource parameterinformation, the method may further include: receiving, by the secondnetwork device, one group of CRS rate matching information sent by thefirst network device, so that the second network device determines,according to the CRS rate matching information, CRS informationcorresponding to transmission of the downlink data.

In the foregoing solution, the transmission point used for initialtransmission may be different from the transmission point used forretransmission; therefore, in a non-ideal backhaul case, for initialtransmission, data may be sent to the UE in a coordinated manner, sothat reliability of data sending is higher.

Embodiment 4

FIG. 5 is a schematic flowchart of another embodiment of a datatransmission method according to the present invention. This embodimentprovides a data transmission method, so that in a non-ideal backhaulscenario, at least two network devices can send data to user equipmentin a coordinated manner to obtain a coordination gain. It should benoted that for descriptions of terms in this embodiment, reference maybe made to descriptions of the same terms in the foregoing embodiments,and details are not described again in this embodiment. In a scenarioillustrated in this embodiment, a base station 0 (which may be referredto as a first network device) is used as a main control network device,a base station 1 (which may be referred to as a second network device)and a base station 2 (which may be referred to as a third networkdevice) jointly transmit downlink data to UE, and the base station 0sends one group of CRS rate matching information to the UE, where thegroup of CRS rate matching information includes CRS informationrespectively corresponding to the base station 1 and the base station 2.It should be noted that for brevity, for related descriptions andspecific details in this embodiment, reference may be made todescriptions in the foregoing embodiments.

501. The second network device transmits downlink data to the userequipment by using a transmission resource parameter, and the thirdnetwork device transmits the downlink data to the user equipment byusing the transmission resource parameter, where the transmissionresource parameter used by the second network device and the thirdnetwork device is configured by the first network device for the secondnetwork device and the third network device.

When the second network device and the third network device jointlytransmit the data to the UE, the second network device and the thirdnetwork device transmit, at at least one subframe, the same downlinkdata to the UE by using same transmission resource parameterinformation, so that the downlink data is jointly transmitted to the UE.Further, before the second network device and the third network devicetransmit, at the at least one subframe, the same downlink data to theuser equipment by using the same transmission resource parameterinformation, the method further includes: receiving, by the secondnetwork device and the third network device, the transmission resourceparameter information notified by the first network device. For example,the base station 1 and the base station 2 are notified of thetransmission resource parameter information by the base station 0.

Certainly, in this embodiment, alternatively, the downlink data may betransmitted by only one of the second network device and the thirdnetwork device to the UE.

502. The first network device receives acknowledgement information sentby the user equipment, or the first network device instructs the secondnetwork device or the third network device to receive acknowledgementinformation, and the second network device or the third network devicethat receives the instruction receives the acknowledgement informationsent by the user equipment, where the first network device notifies theuser equipment of configuration information of a physical uplink controlchannel in advance, and the configuration information of the physicaluplink control channel is used to indicate, for the user equipment,resource configuration information for sending the acknowledgementinformation corresponding to the downlink data.

In the foregoing solution, by means of interaction between networkdevices, in a non-ideal backhaul case, for initial transmission, datamay be sent to the UE in a coordinated manner, so that reliability ofdata sending is higher. In addition, by using the method in thisembodiment of the present invention, the first network device notifiesthe user equipment of the configuration information of the physicaluplink control channel in advance, so that a transmission point forinitial transmission may be different from a transmission point forretransmission.

Further, that the first network device instructs the second networkdevice or the third network device to receive acknowledgementinformation may include: notifying, by the first network device, thesecond network device or the third network device of the configurationinformation of the uplink control channel resource that carries theacknowledgement information. For example, a main control base stationmay also separately notify the UE and a base station that is responsiblefor retransmission, such as the base station 1, of the configurationinformation of the uplink control channel resource that carries theacknowledgement information. In this case, the UE may send, according tothe configuration information, the acknowledgement informationcorresponding to the downlink data, and the base station 1 also knowsthat resource information of the acknowledgement informationcorresponding to the downlink data is to be received by the basestation 1. If the acknowledgement information fed back by the UE is aNACK, the base station 1 retransmits the downlink data to the UE.

503. If the first network device receives the acknowledgementinformation, and when the acknowledgement information is negativeacknowledgement information, the first network device retransmits thedownlink data to the user equipment; or if the second network devicereceives the acknowledgement information, and when the acknowledgementinformation is a negative acknowledgement, the second network deviceretransmits the downlink data to the user equipment; or similarly, ifthe third network device receives the acknowledgement information, andwhen the acknowledgement information is a negative acknowledgement, thethird network device retransmits the downlink data to the userequipment.

Specifically, that the first network device retransmits the downlinkdata to the user equipment may include: if the first network devicereceives the negative acknowledgement information sent by the userequipment, sending, by the first network device to the user equipment,at least one physical downlink control channel for retransmission, wherethe at least one physical downlink control channel for retransmissioncarries second control information, and the second control informationincludes scheduling information of downlink data corresponding to the atleast one physical downlink control channel for retransmission; andretransmitting the downlink data to the user equipment according to thescheduling information; or similarly, that the second network deviceretransmits the downlink data to the user equipment may include: if thesecond network device receives the negative acknowledgement informationsent by the user equipment, sending, by the second network device to theuser equipment, at least one physical downlink control channel forretransmission, where the at least one physical downlink control channelfor retransmission carries second control information, and the secondcontrol information includes scheduling information of downlink datacorresponding to the at least one physical downlink control channel forretransmission. A case for the third network device is similar to theforegoing case, and details are not described herein again.

If initial transmission is executed only by the second network device(that is, step 501), and retransmission is executed by the third networkdevice (that is, step 503), because the first network device is a maincontrol network device, the first network device knows downlink datainitially transmitted by the second network device, and the firstnetwork device configures, for the third network device, the downlinkdata initially transmitted by the second network device, so that thethird network device performs retransmission. The first network deviceknows a moment at which retransmission occurs; therefore, it is onlyrequired to ensure that configuration is complete before retransmissionoccurs.

If initial transmission is executed only by the third network device(that is, step 501), and retransmission is executed by the first networkdevice (that is, step 503), because the first network device is a maincontrol network device, the first network device knows downlink datainitially transmitted by the third network device. Therefore, in thiscase, the first network device can implement retransmission.

Optionally, before the second network device and the third networkdevice transmit, at the at least one subframe, the same downlink data tothe user equipment by using the same transmission resource parameterinformation, the method may further include: receiving, by the secondnetwork device and/or the third network device, one group of CRS ratematching information sent by the first network device, so that thesecond network device and the third network device determine, accordingto the CRS rate matching information, CRS information corresponding totransmission of the downlink data.

Embodiment 5

To understand embodiments of the present invention more clearly, amanner of implementing signaling exchange is provided in thisembodiment, but is not used to limit the foregoing embodiments. FIG. 6is a schematic signaling diagram of another embodiment of an informationconfiguration method according to the present invention. FIG. 6 shows anoptional procedure for transmitting data between a base station and UE,and a scenario shown in FIG. 1 is used as an example, where the UE, abase station 0, and a base station 1 are included. The method includesthe following steps:

601. The base station 0 notifies the base station 1 of determinedtransmission resource parameter information.

In this embodiment, it is assumed that there are only two base stations,that is, the base station 0 and the base station 1, and the base station0 is a main control base station. Therefore, the base station 0determines the transmission resource parameter information, whichincludes, for example, a parameter such as a physical resource used fortransmitting the downlink data, a modulation and coding manner, a datablock size, a time at which a data block is sent, an HARQ process (HARQProcess) number each time a data block is sent, a virtual cell identity(virtual cell-ID) used to generate a scrambling code sequence of a datachannel, or an SPS-C-RNTI (semi-persistent-scheduling C-RNTI), andnotifies the base station 1 of the information. This step is actuallyequivalent to parameter negotiation between the two base stations forcoordinated transmission. The base station 0 configures SPS schedulingfor the user equipment; therefore, the base station configures, for auser, an SPS-C-RNTI exclusive to the SPS scheduling. The base station 0notifies the base station 1 of the SPS-C-RNTI, so that the base station1 and the base station 0 can use the same SPS-C-RNTI to transmit acontrol channel for initial transmission.

602. The base station 0 configures, for the UE, a first resource setgroup of a physical downlink control channel set and a second resourceset group of a physical downlink control channel for retransmission, andsends information about the first resource set group and informationabout the second resource set group to the UE.

In an example of this step, the base station 0 configures the firstresource set group of the physical downlink control channel set and thesecond resource set group of the physical downlink control channel forretransmission, and sends the information about the first resource setgroup and the information about the second resource set group. Forexample, the base station 0 sends the semi-static information of thefirst resource set group and the semi-static information of the secondresource set group to the UE by using higher layer signaling. Certainly,in a specific embodiment, alternatively, the base station 1 may performthe sending, and the like. This embodiment imposes no limitation on anexecution sequence between this step and other steps. For example, thesending may be performed before step 601.

Downlink data indicated by a physical downlink control channel in atleast one subset of the physical downlink control channel set isdownlink data in step 603. The physical downlink control channel forretransmission is a physical downlink control channel for retransmissioncorresponding to the downlink data indicated by the physical downlinkcontrol channel in at least one subset of the physical downlink controlchannel set, that is, a physical downlink control channel correspondingto to-be-retransmitted data in step 607.

The information about the first resource set group may be used by the UEto detect a physical downlink control channel that is in the firstresource set group of the physical downlink control channel set andcorresponding to the downlink data, and the information about the secondresource set group may be used by the UE to detect a physical downlinkcontrol channel that is in the second resource set group of the physicaldownlink control channel for retransmission and corresponding to thedownlink data.

After the base station 0 configures, for the UE, the second resource setgroup of the physical downlink control channel for retransmission, amethod for further determining the second resource set group furtherincludes: notifying, by the base station 0, the UE of a correspondence,where the correspondence is a correspondence between the physicaldownlink control channel in the at least one subset and the secondresource set group. The UE may determine the second resource set groupaccording to the correspondence and at least one received physicaldownlink control channel in the at least one subset of the physicaldownlink control channel set.

Optionally, if reducing complexity of blind detection performed by theuser equipment on the physical downlink control channel is notconsidered, the base station may not execute step 602. It may be assumedthat the user equipment needs to perform blind detection, in allresource sets of physical downlink control channels, for initialtransmission and retransmission in an HARQ process of the userequipment.

It should be noted that step 601 and step 602 are steps preconfigured bythe base station 0, and are used merely as an example herein to describethis embodiment of the present invention; however, step 601 and step 602do not need to be executed each time downlink data is transmitted.

603. The base station 0 and the base station 1 jointly perform initialtransmission of downlink data for the UE.

Both the base station 0 and the base station 1 transmit the samedownlink data to the UE according to the transmission resource parameterinformation determined in step 601, to implement joint transmission.

Further, when the downlink data is being transmitted, the base station 0sends first control information to the UE, where the first controlinformation is carried on the at least one physical downlink controlchannel in the at least one subset of the physical downlink controlchannel set, and includes scheduling information of the downlink data.In this embodiment, the first control information may further includeresource set indication information, and a correspondence between theresource set indication information and the second resource set group isconfigured by a network device or predefined. The UE may determine thesecond resource set group according to the resource set indicationinformation.

In addition, before the downlink data is transmitted, the base station 0may notify the UE of CRS rate matching information corresponding totransmission of the downlink data this time, where the CRS rate matchinginformation includes CRS pattern information respectively correspondingto the base station 0 and the base station 1.

604. The UE receives the initially transmitted downlink data.

Further, the UE detects the physical downlink control channel accordingto the information about the preconfigured first resource set group, andreceives the downlink data according to the first control informationcarried on the detected physical downlink control channel.

605. The base station 0 sends configuration information of a physicaluplink control channel and/or transmit power configuration informationof the physical uplink control channel to the UE.

For the physical downlink control channel in the at least one subset,the network device notifies the user equipment of the configurationinformation of the physical uplink control channel and/or the transmitpower configuration information of the physical uplink control channel,where the physical uplink control channel is used to carryacknowledgement information.

In an example of this step, the base station 0 sends the configurationinformation of the physical uplink control channel and/or the transmitpower configuration information of the physical uplink control channel.For example, the base station 0 notifies the UE of the semi-staticconfiguration information of the physical uplink control channel and/orthe semi-static transmit power configuration information of the physicaluplink control channel by using higher layer signaling. This embodimentimposes no limitation on an execution sequence between this step andother steps. For example, the sending may also be performed before step603 or an earlier step.

606. The UE feeds back acknowledgement information to the base station1.

The configuration information of the physical uplink control channeland/or the transmit power configuration information of the physicaluplink control channel are mainly used by the UE to determine resourceinformation of the corresponding physical uplink control channel thatcarries the initially transmitted downlink data and/or transmit powerinformation of the physical uplink control channel that carries theacknowledgement information, or may be used by the UE to determine abase station to which the acknowledgement information is fed back or abase station that receives the resource information, or may be used bythe UE to determine a base station responsible for retransmission. Forexample, in this embodiment, it is assumed that the base station 1receives the acknowledgement information (an ACK or a NACK) fed back bythe UE, and the base station 1 is responsible for data retransmission.The main control base station, that is, the base station 0, alsonotifies the base station 1 that the base station 1 is responsible forreceiving the acknowledgement information and is responsible forretransmission. Specifically, the base station 0 may also send theconfiguration information of the physical uplink control channel to thebase station 1 in advance, so that the base station 1 learns thatretransmission is to be completed by the base station 1.

For example, the configuration information of the physical uplinkcontrol channel may include resource configuration information of aPUSCH that carries UCI or a PUCCH. A base station that receives theacknowledgement information and is responsible for retransmission is thebase station 1. The base station 0 may also notify the base station 1 ofthe resource configuration information of the PUSCH that carries the UCIor the PUCCH, so that the base station 1 receives the acknowledgementinformation according to the resource configuration information. Foranother example, the transmit power configuration information of thephysical uplink control channel may include power configurationinformation of the PUSCH that carries the UCI or the PUCCH, so that theUE sends the acknowledgement information according to the transmit powerconfiguration information.

For example, if an initially transmitted data packet is correctlyreceived, acknowledgement information fed back by the UE is an ACK, orif an initially transmitted data packet is not correctly received,acknowledgement information fed back by the UE is a NACK.

607. The base station 1 sends retransmission data to the UE.

Before retransmitting the data, the base station 1 has notified, inadvance, the UE of CRS information of a base station responsible forretransmission. For a notification manner of the CRS information of thebase station 1 that retransmits the data, reference may be made to theforegoing embodiments, and details are not described again.

Specifically, that the base station 1 sends retransmission data to theUE includes: if the base station 1 receives the NACK sent by the UE,sending, by the base station 1 to the user equipment, at least one ofthe physical downlink control channel that is for retransmission and inthe second resource set group, where the at least one of the physicaldownlink control channel for retransmission carries second controlinformation, and the second control information includes schedulinginformation of downlink data corresponding to the at least one of thephysical downlink control channel for retransmission; and sending theretransmission data to the UE according to the scheduling information.

608. The UE receives the retransmitted data.

In this embodiment of the present invention, a first network deviceseparately configures, for user equipment, a first resource set groupthat is of a physical downlink control channel set and used for initialtransmission and a second resource set group used for retransmission, sothat the UE can detect, in the preconfigured first resource set groupand second resource set group, a physical downlink control channel usedfor initial transmission and a physical downlink control channel usedfor retransmission. In this way, in an HARQ process, the UE can obtain acoordination gain of multiple resources by using multiple preconfiguredtransmission resources (including resources in the first resource setgroup and the second resource set group). In addition, the first networkdevice separately preconfigures, for the user equipment, the firstresource set group that is of the physical downlink control channel setand used for initial transmission and the second resource set group usedfor retransmission, which reduces complexity of blind detection, whichthe UE performs when obtaining a coordination gain, on the physicaldownlink control channel for retransmission. In addition, in the methodin this embodiment, at least two network devices transmit, to the UE,downlink data by using same transmission resource parameter information,to implement joint transmission, which helps enhance signal receivingperformance and reliability of the UE.

Embodiment 6

FIG. 7 is a schematic structural diagram of an embodiment of a networkdevice according to the present invention. The device in this embodimentmay execute the information configuration method in any embodiment ofthe present invention. As shown in FIG. 7, the device may include aconfiguring unit 71 and a sending unit 72; where

-   -   the configuring unit 71 is configured to: configure a first        resource set group of a physical downlink control channel set        for user equipment, and configure, for the user equipment, a        second resource set group of a physical downlink control channel        for retransmission, where the physical downlink control channel        for retransmission is a physical downlink control channel for        retransmission corresponding to downlink data indicated by a        physical downlink control channel in at least one subset of the        physical downlink control channel set; and    -   the sending unit 72 is configured to send, to the user        equipment, information about the first resource set group and        information about the second resource set group that are        configured by the configuring unit 71.

Further, the sending unit 72 is further configured to: after sending theinformation about the second resource set group to the user equipment,send at least one physical downlink control channel of the physicaldownlink control channel in the at least one subset to the userequipment, where the at least one physical downlink control channelcarries first control information, and the first control informationincludes scheduling information of the downlink data.

The information about the second resource set group sent by the sendingunit 72 to the user equipment includes a correspondence, and thecorrespondence is a correspondence between the physical downlink controlchannel in the at least one subset and the second resource set group ora correspondence between the at least one subset and the second resourceset group. Alternatively, the physical downlink control channel that isin the at least one subset and sent by the sending unit 72 to the userequipment further indicates the second resource set group.

Further, the sending unit 72 is further configured to: for the physicaldownlink control channel in the at least one subset, notify the userequipment of configuration information of a physical uplink controlchannel and/or transmit power configuration information of the physicaluplink control channel, where the physical uplink control channel isused to carry acknowledgement information of the downlink data indicatedby the physical downlink control channel.

FIG. 8 is a schematic structural diagram of another embodiment of anetwork device according to the present invention. The network device isa first network device. As shown in FIG. 8, based on the structure shownin FIG. 7, further, the network device in this embodiment may furtherinclude a receiving unit 73. The receiving unit 73 is configured toreceive negative acknowledgement information sent by the user equipment.The sending unit 72 is further configured to: after the receiving unit73 receives the negative acknowledgement information, send, to the userequipment, at least one of the physical downlink control channel that isfor retransmission and in the second resource set group, where the atleast one of the physical downlink control channel for retransmissioncarries second control information, the second control informationincludes scheduling information of downlink data corresponding to the atleast one of the physical downlink control channel for retransmission,the downlink data corresponding to the at least one of the physicaldownlink control channel for retransmission is sent by a second networkdevice to the user equipment, and the second network device iscontrolled by the first network device.

Further, the sending unit 72 is further configured to: for the physicaldownlink control channel in the at least one subset, notify the userequipment of one group of common reference signal CRS rate matchinginformation, where at least one piece of CRS rate matching informationin the group of CRS rate matching information includes at least twopieces of CRS pattern information, and the at least one piece of CRSrate matching information in the group of CRS rate matching informationis used for rate matching for the downlink data indicated by thephysical downlink control channel in the at least one subset.

Further, the information about the first resource set group sent by thesending unit 72 includes time-frequency resource configurationinformation of the physical downlink control channel set, and/or theinformation about the second resource set group sent by the sending unit72 includes time-frequency resource configuration information of thephysical downlink control channel for retransmission.

The device in this embodiment may execute the information configurationmethod in any embodiment of the present invention; therefore, for acorresponding effect that can be obtained by the device, reference maybe made to descriptions in the foregoing embodiments, and details arenot described herein again.

Embodiment 7

FIG. 9 is a schematic structural diagram of an embodiment of userequipment according to the present invention. The device in thisembodiment may execute the data receiving method in any embodiment ofthe present invention. As shown in FIG. 9, the device may include astorage unit 90, an acquiring unit 91, and a processing unit 92; wherethe storage unit 90 is configured to: store information that is about afirst resource set group of a physical downlink control channel set andsent by a first network device to the user equipment in advance, andstore information that is about a second resource set group of aphysical downlink control channel for retransmission and sent by thefirst network device to the user equipment in advance;

-   -   the acquiring unit 91 is configured to: receive at least one        physical downlink control channel according to the information        that is about the first resource set group and stored by the        storage unit 90, acquire first control information carried on        the at least one physical downlink control channel, and receive        downlink data according to scheduling information that is of the        downlink data and included in the first control information,        where the at least one physical downlink control channel is a        physical downlink control channel in at least one subset of the        physical downlink control channel set; and    -   the processing unit 92 is configured to detect, in the second        resource set group corresponding to the information that is        about the second resource set group and stored by the storage        unit 90, the physical downlink control channel for        retransmission corresponding to the downlink data.

Further, the information that is about the second resource set group andstored by the storage unit 90 includes a correspondence, and thecorrespondence is a correspondence between the physical downlink controlchannel in the at least one subset and the second resource set group, orthe correspondence is a correspondence between the subset of thephysical downlink control channel set and the second resource set group.

The processing unit 92 is further configured to: before detecting, inthe second resource set group, the physical downlink control channel forretransmission corresponding to the downlink data, determine, accordingto the correspondence stored by the storage unit and the at least onephysical downlink control channel received by the acquiring unit, thesecond resource set group corresponding to retransmission of thedownlink data.

Further, the processing unit 92 is further configured to determine,according to an indication in the at least one physical downlink controlchannel received by the acquiring unit 91, the second resource set groupcorresponding to retransmission of the downlink data.

FIG. 10 is a schematic structural diagram of another embodiment of userequipment according to the present invention. As shown in FIG. 10, basedon the structure shown in FIG. 9, the acquiring unit 91 is furtherconfigured to: for the physical downlink control channel in the at leastone subset, receive configuration information that is of a physicaluplink control channel and notified by the first network device. Theprocessing unit 92 is further configured to: after the acquiring unit 91receives the downlink data according to the scheduling information thatis of the downlink data and included in the first control information,determine, according to the configuration information that is of thephysical uplink control channel and acquired by the acquiring unit 91,resource information of the physical uplink control channelcorresponding to the downlink data. The user equipment further includesa sending unit 93, configured to send acknowledgement information of thedownlink data according to the resource information that is of thephysical uplink control channel and determined by the processing unit92.

Further, the acquiring unit 91 is further configured to: if theacknowledgement information sent by the sending unit 93 is negativeacknowledgement information, receive, according to the information aboutthe second resource set group, at least one of the physical downlinkcontrol channel that is for retransmission and in the second resourceset group, where the physical downlink control channel forretransmission carries second control information; and receiveretransmitted downlink data according to scheduling information includedin the second control information, where the scheduling information isscheduling information of the downlink data corresponding to thephysical downlink control channel for retransmission.

Further, the acquiring unit 91 is further configured to: for thephysical downlink control channel in the at least one subset, receivetransmit power configuration information that is of the physical uplinkcontrol channel and notified by the first network device. The sendingunit 93 is specifically configured to send, in the following manner, theacknowledgement information of the downlink data according to theresource information that is of the physical uplink control channel anddetermined by the processing unit: determining transmit powerinformation of the physical uplink control channel according to thetransmit power configuration information acquired by the acquiring unit91, and sending the acknowledgement information of the downlink dataaccording to the resource information and the transmit power informationof the physical uplink control channel.

Further, the acquiring unit 91 is further configured to: for thephysical downlink control channel in the at least one subset, receiveone group of common reference signal CRS rate matching informationnotified by the first network device, where at least one piece of CRSrate matching information in the group of CRS rate matching informationincludes at least two pieces of CRS pattern information.

The acquiring unit 91 is further configured to: before receiving thedownlink data, perform, by using the at least one piece of CRS ratematching information in the group of CRS rate matching information, ratematching on the downlink data indicated by the physical downlink controlchannel in the at least one subset.

Further, the transmit power configuration information received by theacquiring unit 91 includes reference signal power. The sending unit 93is specifically configured to: in the following manner, determine thetransmit power information of the physical uplink control channelaccording to the transmit power configuration information acquired bythe acquiring unit 91, and send the acknowledgement information of thedownlink data according to the resource information and the transmitpower information of the physical uplink control channel: determining adownlink path loss estimate according to the reference signal power,determining transmit power of the physical uplink control channelaccording to the downlink path loss estimate, and sending theacknowledgement information of the downlink data according to theresource information and the transmit power of the physical uplinkcontrol channel.

The device in this embodiment may execute the data receiving method inany embodiment of the present invention; therefore, for a correspondingeffect that can be obtained by the device, reference may be made todescriptions in the foregoing embodiments, and details are not describedherein again.

Embodiment 8

FIG. 11 is a schematic diagram of a physical structure of an embodimentof a network device according to the present invention. The networkdevice is used to implement the information configuration method inembodiments of the present invention, and for an operating principle ofthe network device, reference may be made to the foregoing methodembodiment. As shown in FIG. 11, the network device may include aprocessor 1101 and a transmitter 1102; where

-   -   the processor 1101 is configured to: configure a first resource        set group of a physical downlink control channel set for user        equipment, and configure, for the user equipment, a second        resource set group of a physical downlink control channel for        retransmission, where the physical downlink control channel for        retransmission is a physical downlink control channel for        retransmission corresponding to downlink data indicated by a        physical downlink control channel in at least one subset of the        physical downlink control channel set; and    -   the transmitter 1102 is configured to send, to the user        equipment, information about the first resource set group and        information about the second resource set group that are        configured by the processor 1101.

Further, the transmitter 1102 is further configured to: after sendingthe information about the second resource set group to the userequipment, send at least one physical downlink control channel of thephysical downlink control channel in the at least one subset to the userequipment, where the at least one physical downlink control channelcarries first control information, and the first control informationincludes scheduling information of the downlink data.

Further, the information about the second resource set group sent by thetransmitter includes a correspondence, and the correspondence is acorrespondence between the physical downlink control channel in the atleast one subset and the second resource set group or a correspondencebetween the at least one subset and the second resource set group.Alternatively, the physical downlink control channel that is in the atleast one subset and sent by the transmitter to the user equipmentfurther indicates the second resource set group.

Further, the transmitter 1102 is further configured to: for the physicaldownlink control channel in the at least one subset, notify the userequipment of configuration information of a physical uplink controlchannel and/or transmit power configuration information of the physicaluplink control channel, where the physical uplink control channel isused to carry acknowledgement information.

The device in this embodiment may execute the information configurationmethod in any embodiment of the present invention; therefore, for acorresponding effect that can be obtained by the device, reference maybe made to descriptions in the foregoing embodiments, and details arenot described herein again.

FIG. 12 is a schematic diagram of a physical structure of anotherembodiment of a network device according to the present invention. Asshown in FIG. 12, the network device may further include a receiver1103, configured to receive negative acknowledgement information sent bythe user equipment. The transmitter is further configured to: after thereceiver 1103 receives the negative acknowledgement information, send,to the user equipment, at least one of the physical downlink controlchannel that is for retransmission and in the second resource set group,where the at least one of the physical downlink control channel forretransmission carries second control information, the second controlinformation includes scheduling information of downlink datacorresponding to the at least one of the physical downlink controlchannel for retransmission, the downlink data corresponding to the atleast one of the physical downlink control channel for retransmission issent by a second network device to the user equipment, and the secondnetwork device is controlled by the first network device.

Further, the transmitter 1102 is further configured to: for the physicaldownlink control channel in the at least one subset, notify the userequipment of one group of common reference signal CRS rate matchinginformation, where at least one piece of CRS rate matching informationin the group of CRS rate matching information includes at least twopieces of CRS pattern information, and the at least one piece of CRSrate matching information in the group of CRS rate matching informationis used for rate matching for the downlink data indicated by thephysical downlink control channel in the at least one subset.

Optionally, the information about the first resource set group sent bythe transmitter 1102 includes time-frequency resource configurationinformation of the physical downlink control channel set, and/or theinformation about the second resource set group sent by the transmitter1102 includes time-frequency resource configuration information of thephysical downlink control channel for retransmission.

The device in this embodiment may execute the information configurationmethod in any embodiment of the present invention; therefore, for acorresponding effect that can be obtained by the device, reference maybe made to descriptions in the foregoing embodiments, and details arenot described herein again.

Embodiment 9

FIG. 13 is a schematic diagram of a physical structure of an embodimentof user equipment according to the present invention. The user equipmentis used to implement the data receiving method in embodiments of thepresent invention, and for an operating principle of the user equipment,reference may be made to the foregoing method embodiment. As shown inFIG. 13, the user equipment may include a memory 1300, a receiver 1301,and a processor 1302.

The memory 1300 is configured to: store information that is about afirst resource set group of a physical downlink control channel set andsent by a first network device to the user equipment in advance, andstore information that is about a second resource set group of aphysical downlink control channel for retransmission and sent by thefirst network device to the user equipment in advance;

-   -   the receiver 1301 is configured to: receive at least one        physical downlink control channel according to the information        that is about the first resource set group and stored by the        memory 1300, acquire first control information carried on the at        least one physical downlink control channel, and receive        downlink data according to scheduling information that is of the        downlink data and included in the first control information,        where the at least one physical downlink control channel is a        physical downlink control channel in at least one subset of the        physical downlink control channel set; and    -   the processor 1302 is configured to detect, in the second        resource set group corresponding to the information that is        about the second resource set group and stored by the memory        1300, the physical downlink control channel for retransmission        corresponding to the downlink data.

Further, the processor 1302 is further configured to: before detecting,in the second resource set group, the physical downlink control channelfor retransmission corresponding to the downlink data, determine,according to the correspondence stored by the memory 1300 and the atleast one physical downlink control channel received by the receiver1301, the second resource set group corresponding to retransmission ofthe downlink data.

Further, the processor 1302 is further configured to determine,according to an indication in the at least one physical downlink controlchannel received by the receiver 1301, the second resource set groupcorresponding to retransmission of the downlink data.

FIG. 14 is a schematic diagram of a physical structure of anotherembodiment of user equipment according to the present invention. Asshown in FIG. 14, the receiver 1301 is further configured to: for thephysical downlink control channel in the at least one subset, receiveconfiguration information that is of a physical uplink control channeland notified by the first network device. The processor 1302 is furtherconfigured to: after the receiver 1301 receives the downlink dataaccording to the scheduling information that is of the downlink data andincluded in the first control information, determine, according to theconfiguration information that is of the physical uplink control channeland acquired by the receiver 1301, resource information of the physicaluplink control channel corresponding to the downlink data. The userequipment further includes a transmitter 1303, configured to sendacknowledgement information of the downlink data according to theresource information that is of the physical uplink control channel anddetermined by the processor 1302.

Further, the receiver 1301 is further configured to: if theacknowledgement information sent by the transmitter 1303 is negativeacknowledgement information, receive, according to the information aboutthe second resource set group, at least one of the physical downlinkcontrol channel that is for retransmission and in the second resourceset group, where the physical downlink control channel forretransmission carries second control information; and receiveretransmitted downlink data according to scheduling information includedin the second control information, where the scheduling information isscheduling information of the downlink data corresponding to thephysical downlink control channel for retransmission.

Further, the receiver 1301 is further configured to: for the physicaldownlink control channel in the at least one subset, receive transmitpower configuration information that is of the physical uplink controlchannel and notified by the first network device. The transmitter 1303is specifically configured to send, in the following manner, theacknowledgement information of the downlink data according to theresource information that is of the physical uplink control channel anddetermined by the processor 1302: determining transmit power informationof the physical uplink control channel according to the transmit powerconfiguration information received by the receiver 1301, and sending theacknowledgement information of the downlink data according to theresource information and the transmit power information of the physicaluplink control channel.

Further, the receiver 1301 is further configured to: for the physicaldownlink control channel in the at least one subset, receive one groupof common reference signal CRS rate matching information notified by thefirst network device, where at least one piece of CRS rate matchinginformation in the group of CRS rate matching information includes atleast two pieces of CRS pattern information. The receiver is furtherconfigured to: before receiving the downlink data, perform, by using theat least one piece of CRS rate matching information in the group of CRSrate matching information, rate matching on the downlink data indicatedby the physical downlink control channel in the at least one subset.

Further, the transmit power configuration information received by thereceiver 1301 includes reference signal power. The transmitter 1303 isspecifically configured to: in the following manner, determine thetransmit power information of the physical uplink control channelaccording to the transmit power configuration information acquired bythe receiver 1301, and send the acknowledgement information of thedownlink data according to the resource information and the transmitpower information of the physical uplink control channel: determining adownlink path loss estimate according to the reference signal power,determining transmit power of the physical uplink control channelaccording to the downlink path loss estimate, and sending theacknowledgement information of the downlink data according to theresource information and the transmit power of the physical uplinkcontrol channel.

The device in this embodiment may execute the data receiving method inany embodiment of the present invention; therefore, for a correspondingeffect that can be obtained by the device, reference may be made todescriptions in the foregoing embodiments, and details are not describedherein again.

Embodiment 10

An embodiment provides a data transmission system. As shown in FIG. 15,the system includes a first network device and a second network device.

The first network device is configured to: send a transmission resourceparameter to the second network device, and transmit downlink data touser equipment by using the transmission resource parameter;

-   -   the second network device is configured to transmit the downlink        data to the user equipment by using the transmission resource        parameter sent by the first network device; and    -   the first network device is further configured to:    -   notify the user equipment of configuration information of an        uplink control channel resource, where the configuration        information of the uplink control channel resource is used to        indicate, for the user equipment, resource configuration        information for sending acknowledgement information        corresponding to the downlink data; and    -   receive the acknowledgement information, or instruct the second        network device to receive the acknowledgement information.

The transmission resource parameter in this embodiment may include atleast one of a physical resource used for transmitting the downlinkdata, a modulation and coding manner, a data block size, a time at whicha data block is sent, and an HARQ process number each time a data blockis sent. The first network device and the second network device may sendthe downlink data to the user equipment according to informationincluded in the transmission resource parameter.

When the second network device and the first network device jointlytransmit the data to the UE, the second network device and the firstnetwork device transmit, at at least one subframe, the same downlinkdata to the UE by using the same transmission resource parameter, sothat the downlink data is jointly transmitted to the UE.

If the first network device is further configured to receive theacknowledgement information, and when the acknowledgement information isa negative acknowledgement, the first network device is furtherconfigured to retransmit the downlink data to the user equipment;

-   -   or,    -   if the first network device is further configured to instruct        the second network device to receive the acknowledgement        information, and when the acknowledgement information is a        negative acknowledgement, the second network device is further        configured to retransmit the downlink data to the user        equipment.

Further, the first network device may be specifically configured toinstruct, in the following manner, the second network device to receivethe acknowledgement information:

-   -   notifying, by the first network device, the second network        device of the configuration information of the uplink control        channel resource that carries the acknowledgement information.

Optionally, the second network device is further configured to receiveone group of common reference signal CRS rate matching information sentby the first network device; and

-   -   the first network device is further configured to: before        transmitting the downlink data to the user equipment by using        the transmission resource parameter, determine, from the group        of CRS rate matching information, CRS information corresponding        to transmission of the downlink data, and perform rate matching        by using the determined CRS information; or    -   the second network device is further configured to: before        transmitting the downlink data to the user equipment by using        the transmission resource parameter, determine, from the group        of CRS rate matching information, CRS information corresponding        to transmission of the downlink data, and perform rate matching        by using the determined CRS information.

In the solution in this embodiment, a transmission point used forinitial transmission may be different from a transmission point used forretransmission; therefore, in a non-ideal backhaul case, for initialtransmission, data may be sent to the UE in a coordinated manner, sothat reliability of data sending is higher.

Further, the first network device may also notify the second networkdevice of the configuration information of the uplink control channelresource that carries the acknowledgement information. For example, amain control base station such as a base station 0 may also separatelynotify the UE and a base station that is responsible for retransmission,such as a base station 1, of the configuration information of the uplinkcontrol channel resource that carries the acknowledgement information.In this case, the UE may send, according to the configurationinformation, the acknowledgement information corresponding to thedownlink data, and the base station 1 also knows that resourceinformation of the acknowledgement information corresponding to thedownlink data is to be received by the base station 1. If theacknowledgement information fed back by the UE is a NACK, the basestation 1 retransmits the downlink data to the UE.

Embodiment 11

An embodiment provides a system for implementing data transmission. Asshown in FIG. 16, the system includes a first network device, a secondnetwork device, and a third network device; where

-   -   the first network device is configured to send a transmission        resource parameter to the second network device and/or the third        network device;    -   the second network device is configured to transmit downlink        data to user equipment by using the transmission resource        parameter sent by the first network device; and/or    -   the third network device is configured to transmit the downlink        data to the user equipment by using the transmission resource        parameter sent by the first network device; and    -   the first network device is further configured to:    -   notify the user equipment of configuration information of an        uplink control channel resource, where the configuration        information of the uplink control channel resource is used to        indicate, for the user equipment, resource configuration        information for sending acknowledgement information        corresponding to the downlink data; and    -   receive the acknowledgement information, or instruct the second        network device or the third network device to receive the        acknowledgement information.

If the first network device is further configured to receive theacknowledgement information, and when the acknowledgement information isa negative acknowledgement, the first network device is furtherconfigured to retransmit the downlink data to the user equipment;

-   -   or,    -   if the first network device is further configured to instruct        the second network device to receive the acknowledgement        information, and when the acknowledgement information is a        negative acknowledgement, the second network device is further        configured to retransmit the downlink data to the user        equipment;    -   or,    -   if the first network device is further configured to instruct        the third network device to receive the acknowledgement        information, and when the acknowledgement information is a        negative acknowledgement, the third network device is further        configured to retransmit the downlink data to the user        equipment.

When the second network device and the third network device jointlytransmit the data to the UE, the second network device and the thirdnetwork device transmit, at at least one subframe, the same downlinkdata to the UE by using the same transmission resource parameter, sothat the downlink data is jointly transmitted to the UE. Further, beforethe second network device and the third network device transmit, at theat least one subframe, the same downlink data to the user equipment byusing the same transmission resource parameter, the following is furtherincluded: receiving, by the second network device and the third networkdevice, the transmission resource parameter information notified by thefirst network device. For example, a base station 1 and a base station 2are notified of the transmission resource parameter information by abase station 0 in advance.

Further, that the first network device instructs the second networkdevice or the third network device to receive the acknowledgementinformation may include: notifying, by the first network device, thesecond network device or the third network device of the configurationinformation of the uplink control channel resource that carries theacknowledgement information.

Optionally, the first network device is further configured to notify thesecond network device and/or the third network device of one group ofCRS rate matching information; and

-   -   the second network device is further configured to: before        transmitting the downlink data to the user equipment by using        the transmission resource parameter sent by the first network        device, determine, by using the group of CRS rate matching        information, CRS information corresponding to transmission of        the downlink data, and perform rate matching by using the        determined CRS information; or    -   the third network device is further configured to: before        transmitting the downlink data to the user equipment by using        the transmission resource parameter sent by the first network        device, determine, by using the group of CRS rate matching        information, CRS information corresponding to transmission of        the downlink data, and perform rate matching by using the        determined CRS information.

In the system in this embodiment, in a non-ideal backhaul scenario, atleast two network devices can send data to the user equipment in acoordinated manner to obtain a coordination gain.

Persons of ordinary skill in the art may understand that all or some ofthe steps of the method embodiments may be implemented by a programinstructing related hardware. The program may be stored in acomputer-readable storage medium. When the program runs, the steps ofthe method embodiments are performed. The foregoing storage mediumincludes: any medium that can store program code, such as a ROM, a RAM,a magnetic disk, or an optical disc.

Finally, it should be noted that the foregoing embodiments are merelyintended for describing the technical solutions of the presentinvention, but not for limiting the present invention. Although thepresent invention is described in detail with reference to the foregoingembodiments, persons of ordinary skill in the art should understand thatthey may still make modifications to the technical solutions describedin the foregoing embodiments or make equivalent replacements to some orall technical features thereof, without departing from the scope of thetechnical solutions of the embodiments of the present invention.

What is claimed is:
 1. A network device, comprising: a processor; amemory coupled to the processor, the memory comprising instructionsthat, when executed by the processor, cause the network device to:configure a first resource set group of a physical downlink controlchannel set for a terminal device, and configure, for the terminaldevice, a second resource set group of a physical downlink controlchannel for retransmission, wherein the physical downlink controlchannel for retransmission is a physical downlink control channel forretransmission corresponding to downlink data indicated by a physicaldownlink control channel in at least one subset of the physical downlinkcontrol channel set; and send, to the terminal device, information aboutthe first resource set group and information about the second resourceset group; send at least one physical downlink control channel of thephysical downlink control channel in the at least one subset to theterminal device, wherein the at least one physical downlink controlchannel carries first control information, and the first controlinformation comprises scheduling information of the downlink data. 2.The network device according to claim 1, wherein: the information aboutthe second resource set group comprises a correspondence, and thecorrespondence is between the physical downlink control channel in theat least one subset and the second resource set group or between the atleast one subset and the second resource set group.
 3. The networkdevice according to claim 1, wherein: the memory comprises instructionsthat, when executed by the processor, cause the network device to: forthe physical downlink control channel in the at least one subset, notifythe terminal device of configuration information of a physical uplinkcontrol channel and/or transmit power configuration information of thephysical uplink control channel, wherein the physical uplink controlchannel is used to carry acknowledgement information of the downlinkdata indicated by the physical downlink control channel.
 4. The networkdevice according to claim 1, wherein the network device is a firstnetwork device; the memory comprises instructions that, when executed bythe processor, cause the network device to: receive negativeacknowledgement information from the terminal device; and send, to theterminal device, at least one of the physical downlink control channelthat is for retransmission and in the second resource set group, whereinthe at least one of the physical downlink control channel forretransmission carries second control information, the second controlinformation comprises scheduling information of downlink datacorresponding to the at least one of the physical downlink controlchannel for retransmission, the downlink data corresponding to the atleast one of the physical downlink control channel for retransmission issent by a second network device to the terminal device, and the secondnetwork device is controlled by the first network device.
 5. A terminaldevice, comprising: a processor; a memory coupled to the processor, thememory comprising instructions that, when executed by the processor,cause the terminal device to: store information that is about a firstresource set group of a physical downlink control channel set and sentby a first network device to the terminal device, and store informationthat is about a second resource set group of a physical downlink controlchannel for retransmission and sent by the first network device to theterminal device; receive at least one physical downlink control channelaccording to the information that is about the first resource set group;acquire first control information carried on the at least one physicaldownlink control channel; receive downlink data according to schedulinginformation that is of the downlink data and comprised in the firstcontrol information, wherein the at least one physical downlink controlchannel is a physical downlink control channel in at least one subset ofthe physical downlink control channel set; and detect, in the secondresource set group corresponding to the information that is about thesecond resource set group, wherein the physical downlink control channelfor retransmission corresponding to the downlink data; wherein theinformation that is about the second resource set group comprises acorrespondence, and the correspondence is a correspondence between thephysical downlink control channel in the at least one subset and thesecond resource set group, or the correspondence is a correspondencebetween the subset of the physical downlink control channel set and thesecond resource set group; and before detecting, in the second resourceset group, the physical downlink control channel for retransmissioncorresponding to the downlink data, determine, according to thecorrespondence and the at least one physical downlink control channel,the second resource set group corresponding to retransmission of thedownlink data.
 6. The terminal device according to claim 5, wherein: thememory comprising instructions that, when executed by the processor,cause the terminal device to: for the physical downlink control channelin the at least one subset, receive configuration information that is ofa physical uplink control channel and notified by the first networkdevice; after receiving the downlink data according to the schedulinginformation that is of the downlink data and comprised in the firstcontrol information, determine, according to the configurationinformation that is of the physical uplink control channel, resourceinformation of the physical uplink control channel corresponding to thedownlink data; and send acknowledgement information of the downlink dataaccording to the resource information that is of the physical uplinkcontrol channel.
 7. The terminal device according to claim 5, wherein:the memory comprising instructions that, when executed by the processor,cause the terminal device to: if the acknowledgement information isnegative acknowledgement information, receive, according to theinformation about the second resource set group, at least one of thephysical downlink control channel that is for retransmission and in thesecond resource set group, wherein the physical downlink control channelfor retransmission carries second control information; and receiveretransmitted downlink data according to scheduling informationcomprised in the second control information, wherein the schedulinginformation is scheduling information of the downlink data correspondingto the physical downlink control channel for retransmission.